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Table Of Contents
default-information originate (BGP)
default-information originate (EGP)
default-information originate (IS-IS)
default-information originate (OSPF)
default-metric (BGP, EGP, OSPF, and RIP)
default-metric (IGRP and Enhanced IGRP only)
ip dvmrp routehog-notification
neighbor advertisement-interval
neighbor peer-group (creating)
neighbor peer-group (assigning members)
network (IGRP and Enhanced IGRP)
show ip ospf retransmission-list
IP Routing Protocols Commands
Cisco's implementation of the Internet Protocol (IP) suite provides all major services contained in the TCP/IP specifications.
Use the commands in this chapter to configure and monitor the IP routing protocols. For IP routing protocol configuration information and examples, refer to the "Configuring IP Routing Protocols" chapter of the Router Products Configuration Guide.
aggregate-address
To create an aggregate entry in a BGP routing table, use the aggregate-address router configuration command. To disable this feature, use the no form of this command.
aggregate-address address mask [as-set] [summary-only] [suppress-map map-name]
[advertise-map map-name] [attribute-map map-name]
no aggregate-address address mask [as-set] [summary-only] [suppress-map map-name]
[advertise-map map-name] [attribute-map map-name]Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
You can implement aggregate routing in BGP either by redistributing an aggregate route into BGP or by using this conditional aggregate routing feature.
Using the aggregate-address command with no arguments will create an aggregate entry in the BGP routing table if there are any more-specific BGP routes available that fall in the specified range. The aggregate route will be advertised as coming from your autonomous system and has the atomic aggregate attribute set to show that information might be missing. (By default, the atomic aggregate attribute is set unless you specify the as-set keyword.)
Using the as-set keyword creates an aggregate entry using the same rules that the command follows without this keyword, but the path advertised for this route will be an AS_SET consisting of all elements contained in all paths that are being summarized. Do not use this form of aggregate-address when aggregating many paths, because this route must be continually withdrawn and re-updated as autonomous system path reachability information for the summarized routes changes.
Using the summary-only keyword not only creates the aggregate route (for example, 193.*.*.*) but will also suppress advertisements of more specific routes to all neighbors. If you only want to suppress advertisements to certain neighbors, you may use the neighbor distribute-list command, with caution. If a more specific route leaks out, all BGP speakers will prefer that route over the less specific aggregate you are generating (using longest-match routing).
Using the suppress-map keyword creates the aggregate route but suppresses advertisement of specified routes. You can use the match clauses of route maps to selectively suppress some more specific routes of the aggregate and leave others unsuppressed. IP access lists and autonomous system path access lists match clauses are supported.
Example
In the following example, an aggregate address is created. The path advertised for this route will be an AS_SET consisting of all elements contained in all paths that are being summarized.
router bgp 5aggregate-address 193.0.0.0 255.0.0.0 as-setRelated Commands
match as-path
match ip address
route-maparea authentication
To enable authentication for an OSPF area, use the area authentication router configuration command. To remove an area's authentication specification or a specified area from the router's configuration, use the no form of this command.
area area-id authentication [message-digest]
no area area-id authentication
no area area-idSyntax Description
Default
Type 0 authentication (no authentication)
Command Mode
Router configuration
Usage Guidelines
Specifying authentication for an area sets the authentication to Type 1 (simple password) as specified in RFC 1247. If this command is not included in the configuration file, authentication of Type 0 (no authentication) is assumed.
The authentication type must be the same for all routers in an area. The authentication password for all OSPF routers on a network must be the same if they are to communicate with each other via OSPF. Use the ip ospf authentication-key command to specify this password.
If you enable MD5 authentication with the message-digest keyword, you must configure a password with the ip ospf message-digest-key command.
To remove the area's authentication specification, use the no form of this command with the authentication keyword. To remove the specified area from the router's configuration, use the command no area area-id (with no other keywords).
Example
The following example mandates authentication for areas 0 and 36.0.0.0 of OSPF routing process 201. Authentication keys are also provided.
interface ethernet 0ip address 131.119.251.201 255.255.255.0ip ospf authentication-key adcdefgh!interface ethernet 1ip address 36.56.0.201 255.255.0.0ip ospf authentication-key ijklmnop!router ospf 201network 36.0.0.0 0.255.255.255 area 36.0.0.0network 131.119.0.0 0.0.255.255 area 0area 36.0.0.0 authenticationarea 0 authenticationRelated Commands
area default-cost
area stub
ip ospf authentication-key
ip ospf message-digest-keyarea default-cost
To specify a cost for the default summary route sent into a stub area, use the area default-cost router configuration command. To remove the assigned default route cost, use the no form of this command.
area area-id default-cost cost
no area area-id default-cost costSyntax Description
Default
Cost of 1
Command Mode
Router configuration
Usage Guidelines
This command is used only on an area border router attached to a stub area.
There are two stub area router configuration commands: the stub and default-cost options of the area command. In all routers attached to the stub area, the area should be configured as a stub area using the stub option of the area command. Use the default-cost option only on an area border router attached to the stub area. The default-cost option provides the metric for the summary default route generated by the area border router into the stub area.
Example
The following example assigns a default-cost of 20 to stub network 36.0.0.0:
interface ethernet 0ip address 36.56.0.201 255.255.0.0!router ospf 201network 36.0.0.0 0.255.255.255 area 36.0.0.0area 36.0.0.0 stubarea 36.0.0.0 default-cost 20Related Commands
area-password
To configure the IS-IS area authentication password, use the area-password router configuration command. To disable the password, use the no form of this command.
area-password password
no area-password [password]Syntax Description
Default
No area password is defined.
Command Mode
Router configuration
Usage Guidelines
This password is inserted in Level 1 (station router level) link state PDUs (LSPs), complete sequence number PDUs (CSNPs), and partial sequence number PDUs (PSNP).
Example
The following example assigns an area authentication password:
router isisarea-password angelRelated Command
area range
To consolidate and summarize routes at an area boundary, use the area range router configuration command. To disable this function, use the no form of this command.
area area-id range address mask
no area area-id range address maskSyntax Description
area-id
Identifier of the area about which routes are to be summarized. It can be specified as either a decimal value or as an IP address.
address
IP address.
mask
IP mask.
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
The area range command is used only with area border routers. It is used to consolidate or summarize routes for an area. The result is that a single summary route is advertised to other areas by the area border router. Routing information is condensed at area boundaries. External to the area, a single route is advertised for each address range. This is called route summarization.
Multiple area router configuration commands specifying the range option can be configured. Thus, OSPF can summarize addresses for many different sets of address ranges.
Example
The following example specifies one summary route to be advertised by the area border router to other areas for all subnets on network 36.0.0.0 and for all hosts on network 192.42.110.0:
interface ethernet 0ip address 192.42.110.201 255.255.255.0!interface ethernet 1ip address 36.56.0.201 255.255.0.0!router ospf 201network 36.0.0.0 0.255.255.255 area 36.0.0.0network 192.42.110.0 0.0.0.255 area 0area 36.0.0.0 range 36.0.0.0 255.0.0.0area 0 range 192.42.110.0 255.255.255.0area stub
To define an area as a stub area, use the area stub router configuration command. To disable this function, use the no form of this command.
area area-id stub [no-summary]
no area area-id stubSyntax Description
Default
No stub area is defined.
Command Mode
Router configuration
Usage Guidelines
You must configure the area stub command on all routers in the stub area. Use the area router configuration command with the default-cost option to specify the cost of a default internal router sent into a stub area by an area border router.
There are two stub area router configuration commands: the stub and default-cost options of the area router configuration command. In all routers attached to the stub area, the area should be configured as a stub area using the stub option of the area command. Use the default-cost option only on an area border router attached to the stub area. The default-cost option provides the metric for the summary default route generated by the area border router into the stub area.
To further reduce the number of link state advertisements (LSA) sent into a stub area, you can configure no-summary on the Area Border Router (ABR) to prevent it from sending summary link advertisement (LSA type 3) into the stub area.
Example
The following example assigns a default cost of 20 to stub network 36.0.0.0:
interface ethernet 0ip address 36.56.0.201 255.255.0.0!router ospf 201network 36.0.0.0 0.255.255.255 area 36.0.0.0area 36.0.0.0 stubarea 36.0.0.0 default-cost 20Related Commands
area authentication
area default-costarea virtual-link
To define an OSPF virtual link, use the area virtual-link router configuration command with the optional parameters. To remove a virtual link, use the no form of this command.
area area-id virtual-link router-id [hello-interval seconds] [retransmit-interval seconds]
[transmit-delay seconds] [dead-interval seconds] [[authentication-key key] |
[message-digest-key keyid md5 key]]
no area area-id virtual-link router-id [hello-interval seconds] [retransmit-interval seconds]
[transmit-delay seconds] [dead-interval seconds] [[authentication-key key] |
[message-digest-key keyid md5 key]]Syntax Description
Default
area-id: No area ID is predefined.
router-id: No router ID is predefined.
hello-interval seconds: 10 seconds
retransmit-interval seconds: 10 seconds
transmit-delay seconds: 1 second
dead-interval seconds: 40 seconds
authentication-key key: No key is predefined.
message-digest-key keyid md5 key: No key is predefined.Command Mode
Router configuration
Usage Guidelines
In OSPF, all areas must be connected to a backbone area. If the connection to the backbone is lost, it can be repaired by establishing a virtual link.
The smaller the Hello interval, the faster topological changes will be detected, but more routing traffic will ensue.
The setting of the retransmit interval should be conservative, or needless retransmissions will result. The value should be larger for serial lines and virtual links.
The transmit delay value should take into account the transmission and propagation delays for the interface.
A router will use the specified authentication key only when authentication is enabled for the backbone with the area area-id authentication router configuration command.
The two authentication schemes, simple text and MD5 authentication, are mutually exclusive. You can specify one or the other or neither. Any keywords and arguments you specify after authentication-key key or message-digest-key keyid md5 key are ignored. Therefore, specify any optional arguments before such a keyword-argument combination.
Note
Each virtual link neighbor must include the transit area ID and the corresponding virtual link neighbor's router ID in order for a virtual link to be properly configured. Use the show ip ospf EXEC command to see the router ID of a router.
Examples
The following example establishes a virtual link with default values for all optional parameters:
router ospf 201network 36.0.0.0 0.255.255.255 area 36.0.0.0area 36.0.0.0 virtual-link 36.3.4.5The following example establishes a virtual link with MD5 authentication:
router ospf 201network 36.0.0.0 0.255.255.255 area 36.0.0.0area 36.0.0.0 virtual-link 36.3.4.5 message-digest-key 3 md5 sa5721bk47Related Commands
A dagger (†) indicates that the command is documented in another chapter.
area authentication
service password-encryption †
show ip ospfautonomous-system (EGP)
To specify the local autonomous system that the router resides in for EGP, use the autonomous-system global configuration command. To remove the autonomous system number, use the no form of this command.
autonomous-system local-as
no autonomous-system local-asSyntax Description
Default
No local autonomous system is specified.
Command Mode
Global configuration
Usage Guidelines
Before you can set up EGP routing, you must specify an autonomous system number. The local autonomous system number will be included in EGP messages sent by the router.
Example
The following sample configuration specifies an autonomous system number of 110:
autonomous-system 110Related Command
auto-summary
To restore the default behavior of automatic summarization of subnet routes into network-level routes, use the auto-summary router configuration command. To disable this feature, use the no form of this command.
auto-summary
no auto-summarySyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Router configuration
Usage Guidelines
By default, BGP does not accept subnets redistributed from IGP. To advertise and carry subnet routes in BGP, use an explicit network command or the no auto-summary command. If you disable auto-summarization and have not entered a network command, you will not advertise network routes for networks with subnet routes unless they contain a summary route.
IP Enhanced IGRP summary routes are given an administrative distance value of 5. You cannot configure this value.
Examples
In the following example, network numbers are not summarized automatically:
router bgp 6no auto-summaryThe following example disables automatic summarization for router process eigrp 109:
router eigrp 109no auto-summaryRelated Command
bgp always-compare-med
To allow the comparison of the Multi Exit Discriminator (MED) for paths from neighbors in different autonomous systems, use the bgp always-compare-med router configuration command. To disallow the comparison, use the no form of this command.
bgp always-compare-med
no bgp always-compare-medSyntax Description
This command has no arguments or keywords.
Default
The router does not compare MEDs for paths from neighbors in different autonomous systems.
Command Mode
Router configuration
Usage Guidelines
The MED is one of the parameters that is considered when selecting the best path among many alternative paths. The path with a lower MED is preferred over a path with a higher MED.
By default, during the best path selection process, MED comparision is done only among paths from the same autonomous system. This command changes the default behavior by allowing comparision of MEDs among paths regardless of the autonomous system from which the paths are received.
Example
In the following example, the BGP speaker in autonomous system 100 is configured to compare MEDs among alternative paths, regardless of the autonomous system from which the paths are received:
router bgp 109bgp always-compare-medbgp confederation identifier
To specify a BGP confederation identifier, use the bgp confederation identifier router configuration command. To remove the confederation identifier, use the no form of this command.
bgp confederation identifier autonomous-system
no bgp confederation identifier autonomous-systemSyntax Description
Default
No confederation identifier is configured.
Command Mode
Router configuration
Usage Guidelines
Another way to reduce the IBGP mesh is to divide an autonomous system into multiple autonomous systems and group them into a single confederation. Each autonomous system is fully meshed within itself, and has a few connections to another autonomous system in the same confederation. Even though the peers in different autonomous systems have EBGP sessions, they exchange routing information as if they are IBGP peers. Specifically, the next-hop and local preference information is preserved. This enables to you to retain a single Interior Gateway Protocol (IGP) for all of the autonomous systems. To the outside world, the confederation looks like a single autonomous system.
Example
In the following example, the autonomous system is divided into autonomous systems 4001, 4002, 4003, 4004, 4005, 4006, and 4007 and identified by the confederation identifier 5. Neighbor 1.2.3.4 is someone inside your routing domain confederation. Neighbor 3.4.5.6 is someone outside your routing domain confederation. To the outside world, there appears to be a single autonomous system with the number 5.
router bgp 4001bgp confederation identifier 5bgp confederation peers 4002 4003 4004 4005 4006 4007neighbor 1.2.3.4 remote-as 4002neighbor 3.4.5.6 remote-as 510Related Command
bgp confederation peers
To configure the autonomous systems that belong to the confederation, use the bgp confederation peers router configuration command. To remove an autonomous system from the confederation, use the no form of this command.
bgp confederation peers autonomous-system [autonomous-system]
no bgp confederation peers autonomous-system [autonomous-system]Syntax Description
Default
No confederation peers are configured.
Command Mode
Router configuration
Usage Guidelines
The autonomous systems specified in this command are visible internally to a confederation. Each autonomous system is fully meshed within itself. The bgp confederation identifier command specifies the confederation that the autonomous systems belong to.
Example
The following example specifies that autonomous systems 1090, 1091, 1092, and 1093 belong to a single confederation:
router bgp 1090bgp confederation peers 1091 1092 1093Related Command
bgp default local-preference
To change the default local preference value, use the bgp default local-preference router configuration command. To return to the default setting, use the no form of this command.
bgp default local-preference value
no bgp default local-preference valueSyntax Description
Default
Local preference value of 100
Command Mode
Router configuration
Usage Guidelines
Generally, the default value of 100 allows you to easily define a particular path as less preferable than paths with no local preference attribute. The preference is sent to all routers in the local autonomous system.
Example
In the following example, the default local preference value is raised from the default of 100 to 200:
router bgp 200bgp default local-preference 200Related Command
bgp fast-external-fallover
To immediately reset the BGP sessions of any directly adjacent external peers if the link used to reach them goes down, use the bgp fast-external-fallover router configuration command. To disable this feature, use the no form of this command.
bgp fast-external-fallover
no bgp fast-external-falloverSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Router configuration
Example
In the following example, the automatic resetting of BGP sessions is disabled:
router bgp 109no bgp fast-external-falloverbgp log-neighbor-changes
To enable logging of BGP neighbor resets, use the bgp log-neighbor-changes router configuration command. To disable the logging of changes in BGP neighbor adjacencies, use the no form of this command.
bgp log-neighbor-changes
no bgp log-neighbor-changesSyntax Description
This command has no arguments or keywords.
Default
No BGP neighbor changes are logged.
Command Mode
Router configuration
Usage Guidelines
The bgp log-neighbor-changes command enables logging of BGP neighbor status changes (up or down) and resets for troubleshooting network connectivity problems and measuring network stability. Unexpected neighbor resets might indicate high error rates or high packet loss in the network and should be investigated.
Using the bgp log-neighbo-changes command to enable status change message logging does not create a significant performance hit, unlike, for example, enabling per BGP update debugging. If the UNIX syslog facility is enabled, messages are sent to the UNIX host running the syslog daemon so that the messages can be stored and archived. If the UNIX syslog facility is not enabled, the status change messages are retained in the router's internal buffer, and are not stored to disk. You can set the size of this buffer, which is dependent upon the available RAM, using the logging buffered command.
The neighbor status change messages are not tracked if bgp log-neighbor changes is not enabled, except for the reset reason, which is always available as output of the show ip bgp neighbor command.
The log messages display the following reasons for changes in a neighbor's status:
BGP protocol initialization
No memory for path entry
No memory for attribute entry
No memory for prefix entry
No memory for aggregate entry
No memory for dampening info
No memory for BGP updates
BGP Notification received
Erroneous BGP Update received
User reset request
Peer timeout
Password change
Error during connection collision
Peer closing down the session
Peer exceeding maximum prefix limit
Interface flap
Router ID changed
Neighbor deleted
Member added to peergroup
Administratively shutdown
Remote AS changed
RR client configuration modification
Soft reconfiguration modificationThe eigrp log-neighbor-changes command enables logging of Enhanced IGRP neighbor adjacencies, but messages for BGP neighbors are logged only if they are specifically enabled with the bgp log-neighbor-changes command.
Use the show logging command to display the log for the BGP neighbor changes.
Example
The following configuration will log neighbor changes for BGP:
bgp router 100bgp log-neighbor-changes
Related Commands
You can use the master indexes or search online to find documentation of related commands.
logging buffered
show ip bgp neighbor
show loggingclear arp-cache
To remove all dynamic entries from the ARP cache and to clear the fast-switching cache, use the clear arp-cache EXEC command.
clear arp-cache
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Example
The following example removes all dynamic entries from the ARP cache and clears the fast-switching cache:
clear arp-cacheclear ip bgp
To reset a BGP connection, use the clear ip bgp EXEC command at the system prompt.
clear ip bgp {* | address}
Syntax Description
Command Mode
EXEC
Usage Guidelines
Use this command whenever any of the following changes occur:
•
•
•
•
•
•
Example
The following example resets all current BGP sessions:
clear ip bgp *Related Commands
clear ip bgp peer-group
To remove all of the members of a BGP peer group, use the clear ip bgp peer-group EXEC command.
clear ip bgp peer-group tag
Syntax Description
Command Mode
EXEC
Example
The following example removes all members from the BGP peer group internal:
clear ip bgp peer-group internalRelated Command
neighbor peer-group (assigning members)
clear ip dvmrp route
To delete routes from the DVMRP routing table, use the clear ip dvmrp route EXEC command.
clear ip dvmrp route {* | route}
Syntax Description
*
Clears all routes.
route
Clears the longest matched route. Can be an IP address, a network number, or an IP DNS name.
Command Mode
EXEC
Examples
The following example deletes route 10.1.1.1 from the DVMRP routing table:
clear ip dvmrp route 10.1.1.1The following example deletes network 10.0.0.0 from the DVMRP routing table:
clear ip dvmrp route 10.0.0.0clear ip eigrp neighbors
To delete entries from the neighbor table, use the clear ip eigrp neighbors EXEC command.
clear ip eigrp neighbors [ip-address | type number]
Syntax Description
ip-address
(Optional) Address of the neighbor.
type number
(Optional) Interface type and number. Specifying these arguments removes from the neighbor table all entries learned via this interface.
Command Mode
EXEC
Example
The following example removes the neighbor whose address is 160.20.8.3:
clear ip eigrp neighbors 160.20.8.3Related Command
clear ip igmp group
To delete entries from the IGMP cache, use the clear ip igmp group EXEC command.
clear ip igmp group [group-name | group-address | type number]
Syntax Description
Command Mode
EXEC
Usage Guidelines
The IGMP cache contains a list of the multicast groups of which hosts on the directly connected LAN are members. If the router has joined a group, it is also listed in the cache.
To delete all entries from the IGMP cache, specify the clear ip igmp group command with no arguments.
Example
The following example clears entries for the multicast group 224.0.255.1 from the IGMP cache:
clear ip igmp group 224.0.255.1Related Commands
A dagger (†) indicates that the command is documented in another chapter.
ip host †
show ip igmp groups
show ip igmp interfaceclear ip mroute
To delete entries from the IP multicast routing table, use the clear ip mroute EXEC command.
clear ip mroute {* | group [source]}
Syntax Description
Command Mode
EXEC
Examples
The following example deletes all entries from the IP multicast routing table:
clear ip mroute *The following example deletes from the IP multicast routing table all sources on the 10.3.0.0 subnet that are transmitting to the multicast group 224.2.205.42. Note that this example deletes all sources on network 10.3, not individual sources.
clear ip mroute 224.2.205.42 10.3.0.0Related Commands
A dagger (†) indicates that the command is documented in another chapter.
ip host †
show ip mrouteclear ip route
To remove one or more routes from the IP routing table, use the clear ip route EXEC command.
clear ip route {network [mask] | *}
Syntax Description
network
Network or subnet address to remove.
mask
(Optional) Network mask associated with the IP address you wish to remove.
*
Removes all entries.
Command Mode
EXEC
Example
The following example removes a route to network 132.5.0.0 from the IP routing table:
clear ip route 132.5.0.0Related Command
clear ip sd
To delete a session directory cache entry, use the clear ip sd EXEC command.
clear ip sd [group-address | "session-name"]
Syntax Description
Command Mode
EXEC
Usage Guidelines
If neither argument is specified, the entire session directory cache is deleted.
Examples
The following example deletes the entire session directory cache:
clear ip sdThe following example deletes sessions with the group address 224.2.0.1 from the session directory cache:
clear ip sd 224.2.0.1The following example deletes the session entry called mbone audio from the session directory cache:
clear ip sd "mbone audio"Related Command
default-information allowed
To control the candidate default routing information between IGRP or Enhanced IGRP processes, use the default-information allowed router configuration command. To suppress IGRP or Enhanced IGRP candidate information in incoming updates, use the no default-information allowed in command. To suppress IGRP or Enhanced IGRP candidate information in outbound updates, use the no default-information allowed out command.
default-information allowed {in | out} [route-map map-tag]
no default-information allowed {in | out} [route-map map-tag]Syntax Description
Default
Normally, exterior routes are always accepted and default information is passed between IGRP or Enhanced IGRP processes when doing redistribution.
Command Mode
Router configuration
Usage Guidelines
The default network of 0.0.0.0 used by RIP cannot be redistributed by IGRP or Enhanced IGRP.
Example
The following example allows IGRP exterior or default routes to be received by the IGRP process in autonomous system 23:
router igrp 23default-information allowed indefault-information originate (BGP)
To allow the redistribution of network 0.0.0.0 into BGP, use the default-information originate router configuration command. To disable this feature, use the no form of this command.
default-information originate
no default-information originateSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
The same functionality will result from the network 0.0.0.0 command, using the network router configuration command.
Example
The following example configures BGP to redistribute network 0.0.0.0 into BGP:
router bgp 164default-information originatedefault-information originate (EGP)
To explicitly configure EGP to generate a default route, use the default-information originate router configuration command. To disable this feature, use the no form of this command.
default-information originate
no default-information originateSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
Because EGP can use network 0.0.0.0 as a default route, EGP must be explicitly configured to generate a default route. If the next hop for the default route can be advertised as a third party, it will be included as a third party.
Example
The following example configures EGP to generate a default route:
autonomous system 109router egp 164network 131.108.0.0network 192.31.7.0neighbor 10.2.0.2default-information originatedefault-information originate (IS-IS)
To generate a default route into an IS-IS routing domain, use the default-information originate router configuration command. To disable this feature, use the no form of this command.
default-information originate [route-map map-name]
no default-information originate [route-map map-name]Syntax Description
route-map map-name
(Optional) Routing process will generate the default route if the route map is satisfied.
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
If a router configured with this command has a route to 0.0.0.0 in the routing table, IS-IS will originate an advertisement for 0.0.0.0 in its LSPs.
Example
In the following configuration, the router is forced to generate a default external route into an IS-IS domain:
router isis! BGP routes will be distributed into IS-ISredistribute bgp 120! access list 2 is applied to outgoing routing updatesdistribute-list 2 outdefault-information originate! access list 2 defined as giving access to network 100.105.0.0access-list 2 permit 100.105.0.0 0.0.255.255Related Commands
default-information originate (OSPF)
To generate a default route into an OSPF routing domain, use the default-information originate router configuration command. To disable this feature, use the no form of this command.
default-information originate [always] [metric metric-value] [metric-type type-value]
{level-1 | level-1-2 | level-2} [route-map map-name]
no default-information originate [always] [metric metric-value] [metric-type type-value]
{level-1 | level-1-2 | level-2} [route-map map-name]Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
Whenever you use the redistribute or the default-information router configuration commands to redistribute routes into an OSPF routing domain, the router automatically becomes an autonomous system boundary router. However, an autonomous system boundary router does not, by default, generate a default route into the OSPF routing domain. The router still needs to have a default route for itself before it generates one, except when you have specified the always keyword.
When you use this command for the OSPF process, the default network must reside in the routing table and you must satisfy the route-map map-name keyword. Use the default-information originate always route-map map-name form of the command when you do not want the dependency on the default network in the routing table.
Example
The following example specifies a metric of 100 for the default route redistributed into the OSPF routing domain and an external metric type of Type 1:
router ospf 109redistribute igrp 108 metric 100 subnetsdefault-information originate metric 100 metric-type 1Related Command
default-metric (BGP, EGP, OSPF, and RIP)
To set default metric values for the BGP, EGP, OSPF, and RIP routing protocols, use this form of the default-metric router configuration command. To return to the default state, use the no form of this command.
default-metric number
no default-metricSyntax Description
Default
Built-in, automatic metric translations, as appropriate for each routing protocol
Command Mode
Router configuration
Usage Guidelines
The default-metric command is used in conjunction with the redistribute router configuration command to cause the current routing protocol to use the same metric value for all redistributed routes. A default metric helps solve the problem of redistributing routes with incompatible metrics. Whenever metrics do not convert, using a default metric provides a reasonable substitute and enables the redistribution to proceed.
In BGP, this sets the multiple exit discriminator (MED) metric. (The name of this metric for BGP Versions 2 and 3 is INTER_AS.)
Example
The following example shows a router in autonomous system 109 using both the RIP and the OSPF routing protocols. The example advertises OSPF-derived routes using the RIP protocol and assigns the OSPF-derived routes a RIP metric of 10.
router ripdefault-metric 10redistribute ospf 109Related Command
default-metric (IGRP and Enhanced IGRP only)
To set metrics for IGRP or Enhanced IGRP, use this form of the default-metric router configuration command. To remove the metric value and restore the default state, use the no form of this command.
default-metric bandwidth delay reliability loading mtu
no default-metric bandwidth delay reliability loading mtuSyntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
Metric defaults have been carefully set to work for a wide variety of networks. Take great care in changing these values.
Keeping the same metrics is supported only when redistributing from IGRP, Enhanced IGRP, or static routes.
Example
The following example takes redistributed RIP metrics and translates them into IGRP metrics with values as follows: bandwidth = 1000, delay = 100, reliability = 250, loading = 100, and mtu =1500.
router igrp 109network 131.108.0.0redistribute ripdefault-metric 1000 100 250 100 1500Related Command
distance
To define an administrative distance, use the distance router configuration command. To remove a distance definition, use the no form of this command.
distance weight [address mask [access-list-number]] [ip]
no distance weight [address mask [access-list-number]] [ip]Syntax Description
Default
lists default administrative distances.
Table 19-1 Default Administrative Distances
Connected interface
0
Static route
1
External BGP
20
IGRP
100
OSPF
110
IS-IS
115
RIP
120
EGP
140
Internal BGP
200
Unknown
255
Command Mode
Router configuration
Usage Guidelines
Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.
When the optional access list number is used with this command, it is applied when a network is being inserted into the routing table. This behavior allows filtering of networks according to the IP address of the router supplying the routing information. This could be used, as an example, to filter out possibly incorrect routing information from routers not under your administrative control.
The order in which you enter distance commands can affect the assigned administrative distances in unexpected ways (see "Example" for further clarification).
Weight values are also subjective; there is no quantitative method for choosing weight values.
For BGP, the distance command sets the administrative distance of the External BGP route.
The show ip protocols EXEC command displays the default administrative distance for a specified routing process.
Example
In the following example, the router igrp global configuration command sets up IGRP routing in autonomous system number 109. The network router configuration commands specify IGRP routing on networks 192.31.7.0 and 128.88.0.0. The first distance router configuration command sets the default administrative distance to 255, which instructs the router to ignore all routing updates from routers for which an explicit distance has not been set. The second distance command sets the administrative distance for all routers on the Class C network 192.31.7.0 to 90. The third distance command sets the administrative distance for the router with the address 128.88.1.3 to 120.
router igrp 109network 192.31.7.0network 128.88.0.0distance 255distance 90 192.31.7.0 0.0.0.255distance 120 128.88.1.3 0.0.0.0Related Command
distance bgp
To allow the use of external, internal, and local administrative distances that could be a better route to a node, use the distance bgp router configuration command. To return to the default values, use the no form of this command.
distance bgp external-distance internal-distance local-distance
no distance bgpSyntax Description
Default
external-distance: 20
internal-distance: 200
local-distance: 200Command Mode
Router configuration
Usage Guidelines
An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.
Use this command if another protocol is known to be able to provide a better route to a node than was actually learned via external BGP, or if some internal routes should really be preferred by BGP.
Note
Example
In the following example, internal routes are known to be preferable to those learned through the IGP, so the administrative distance values are set accordingly:
router bgp 109network 131.108.0.0neighbor 129.140.6.6 remote-as 123neighbor 128.125.1.1 remote-as 47distance bgp 20 20 200Related Command
distance eigrp
To allow the use of two administrative distances—internal and external—that could be a better route to a node, use the distance eigrp router configuration command. To reset these values to their defaults, use the no form of this command.
distance eigrp internal-distance external-distance
no distance eigrpSyntax Description
Default
internal-distance: 90
external-distance: 170Command Mode
Router configuration
Usage Guidelines
An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.
Use the distance eigrp command if another protocol is known to be able to provide a better route to a node than was actually learned via external Enhanced IGRP or if some internal routes should really be preferred by Enhanced IGRP.
lists the default administrative distances.
Table 19-2 Default Administrative Distances
To display the default administrative distance for a specified routing process, use the show ip protocols EXEC command.
Example
In the following example, the router eigrp global configuration command sets up Enhanced IGRP routing in autonomous system number 109. The network router configuration commands specify Enhanced IGRP routing on networks 192.31.7.0 and 128.88.0.0. The first distance router configuration command sets the default administrative distance to 255, which instructs the router to ignore all routing updates from routers for which an explicit distance has not been set. The second distance router configuration command sets the administrative distance for all routers on the Class C network 192.31.7.0 to 90. The third distance router configuration command sets the administrative distance for the router with the address 128.88.1.3 to 120.
router eigrp 109network 192.31.7.0network 128.88.0.0distance 255!! use caution when executing the next two commands!!distance 90 192.31.7.0 0.0.0.255distance 120 128.88.1.3 0.0.0.0Related Command
distribute-list in
To filter networks received in updates, use the distribute-list in router configuration command. To change or cancel the filter, use the no form of this command.
distribute-list access-list-number in [interface-name]
no distribute-list access-list-number in [interface-name]Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
This command is not supported in IS-IS.
Example
In the following example, the Enhanced IGRP routing process accepts only two networks—network 0.0.0.0 and network 131.108.0.0:
access-list 1 permit 0.0.0.0access-list 1 permit 131.108.0.0access-list 1 deny 0.0.0.0 255.255.255.255router eigrpnetwork 131.108.0.0distribute-list 1 inRelated Commands
A dagger (†) indicates that the command is documented in another chapter.
access-list (standard) †
access-list (extended) †
distribute-list out
redistributedistribute-list out
To suppress networks from being advertised in updates, use the distribute-list out router configuration command. To cancel this function, use the no form of this command.
distribute-list access-list-number out [interface-name | routing-process |
autonomous-system-number]
no distribute-list access-list-number out [interface-name | routing-process |
autonomous-system-number]Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
When redistributing networks, a routing process name can be specified as an optional trailing argument to the distribute-list command. This causes the access list to be applied to only those routes derived from the specified routing process. After the process-specific access list is applied, any access list specified by a distribute-list command without a process name argument will be applied. Addresses not specified in the distribute-list command will not be advertised in outgoing routing updates.
Note
Examples
The following example would cause only one network to be advertised by a RIP routing process: network 131.108.0.0.
access-list 1 permit 131.108.0.0access-list 1 deny 0.0.0.0 255.255.255.255router ripnetwork 131.108.0.0distribute-list 1 outIn the following example, access list 1 is applied to outgoing routing updates and IS-IS is enabled on Ethernet interface 0. Only network 131.131.101.0 will be advertised in outgoing IS-IS routing updates.
router isisredistribute ospf 109distribute-list 1 outinterface Ethernet 0ip router isisaccess-list 1 permit 131.131.101.0 0.0.0.255Related Commands
A dagger (†) indicates that the command is documented in another chapter.
access-list (standard) †
access-list (extended) †
distribute-list in
redistributedomain-password
To configure the IS-IS routing domain authentication password, use the domain-password router configuration command. To disable a password, use the no form of this command.
domain-password password
no domain-password [password]Syntax Description
Default
No password is specified.
Command Mode
Router configuration
Usage Guidelines
This password is inserted in Level 2 (area router level) link state PDUs (LSPs), complete sequence number PDUs (CSNPs), and partial sequence number PDUs (PSNP).
Example
The following example assigns an authentication password to the routing domain:
router isisdomain-password flowerRelated Command
ip as-path access-list
To define a BGP-related access list, use the ip as-path access-list global configuration command. To disable use of the access list, use the no form of this command.
ip as-path access-list access-list-number {permit | deny} as-regular-expression
no ip as-path access-list access-list-number {permit | deny} as-regular-expressionSyntax Description
Default
No access lists are defined.
Command Mode
Global configuration
Usage Guidelines
You can specify an access list filter on both inbound and outbound BGP routes. In addition, you can assign weights based on a set of filters. Each filter is an access list based on regular expressions. If the regular expression matches the representation of the autonomous system path of the route as an ASCII string, then the permit or deny condition applies. The autonomous system path does not contain the local autonomous system number. Use the ip as-path access-list global configuration command to define an BGP access list, and the neighbor router configuration command to apply a specific access list.
Example
The following example specifies that the BGP neighbor with IP address 128.125.1.1 is not sent advertisements about any path through or from the adjacent autonomous system 123.
ip as-path access-list 1 deny _123_ip as-path access-list 1 deny ^123$router bgp 109network 131.108.0.0neighbor 129.140.6.6 remote-as 123neighbor 128.125.1.1 remote-as 47neighbor 128.125.1.1 filter-list 1 outRelated Commands
neighbor distribute-list
neighbor filter-listip community-list
To create a community list for BGP and control access to it, use the ip community-list global configuration command. To delete the community list, use the no form of this command.
ip community-list community-list-number {permit | deny} community-number
no ip community-list community-list-numberSyntax Description
community-list-number
Integer 1 through 99 that identifies one or more permit or deny groups of communities.
permit
Permits access for a matching condition.
deny
Denies access for a matching condition.
community-number
Community number configured by a set community command. Valid value is one of the following:
•
•
•
•
Default
Once you permit a value for the community number, the community list defaults to an implicit deny for everything else.
Command Mode
Global configuration
Example
In the following example, the router permits all routes except the routes with the communities 5 and 10 or 10 and 15:
ip community-list 1 deny 5 10ip community-list 1 deny 10 15ip community-list 1 permit internetRelated Command
ip default-network
To select a network as a candidate route for computing the gateway of last resort, use the ip default-network global configuration command. To remove a route, use the no form of this command.
ip default-network network-number
no ip default-network network-numberSyntax Description
Default
If the router has a directly connected interface onto the specified network, the dynamic routing protocols running on that router will generate (or source) a default route. For RIP, this is flagged as the pseudonetwork 0.0.0.0; for IGRP, it is the network itself, flagged as an exterior route.
Command Mode
Global configuration
Usage Guidelines
The router uses both administrative distance and metric information to determine the default route. Multiple ip default-network commands can be given. All candidate default routes, both static (that is, flagged by ip default-network) and dynamic, appear in the routing table preceded by an asterisk.
If the IP routing table indicates that the specified network number is subnetted and a non-zero subnet number is specified, then the system will automatically configure a static summary route. This static summary route is configured instead of a default network. The effect of the static summary route is to cause traffic destined for subnets that are not explicitly listed in the IP routing table to be routed using the specified subnet.
Examples
The following example defines a static route to network 10.0.0.0 as the static default route:
ip route 10.0.0.0 255.0.0.0 131.108.3.4ip default-network 10.0.0.0
If the following command was issued on a router not connected to network 129.140.0.0, the router might choose the path to that network as a default route when the network appeared in the routing table:
ip default-network 129.140.0.0Related Command
ip dvmrp accept-filter
To configure an acceptance filter for incoming DVMRP reports, use the ip dvmrp accept-filter interface configuration command. To disable this feature, use the no form of this command.
ip dvmrp accept-filter access-list-number [distance]
no ip dvmrp accept-filter access-list-number [distance]Syntax Description
Default
All destinations are accepted with a distance of 0.
Command Mode
Interface configuration
Usage Guidelines
Any sources that match the access list are stored in the DVMRP routing table with distance.
The distance is used to compare with the same source in the unicast routing table. The route with the lower distance (either the route in the unicast routing table or that in the DVMRP routing table) takes precedence when computing the Reverse Path Forwarding (RPF) interface for a source of a multicast packet.
By default, the administrative distance for DVMRP routes is 0. This means that they always take precedence over unicast routing table routes. If you have two paths to a source, one through unicast routing (using PIM as the multicast routing protocol) and another path using DVMRP (unicast and multicast routing), and if you want to use the PIM path, use the ip dvmrp accept-filter command to increase the administrative distance for DVMRP routes. For example, if the unicast routing protocol is Enhanced IGRP, which has a default administrative distance of 90, you could define and apply the following access list so the RPF interface used to accept multicast packets will be through the Enhanced IGRP/PIM path:
ip dvmrp accept-filter 1 100access-list 1 permit 0.0.0.0 255.255.255.255Example
The following example applies access list 57 to the interface and sets a distance of 4:
access-list 57 permit 131.108.0.0 0.0.255.255access-list 57 permit 198.92.37.0 0.0.0.255access-list 57 deny 0.0.0.0 255.255.255.255ip dvmrp accept-filter 57 4Related Commands
A dagger (†) indicates that the command is documented in another chapter.
distance
ip dvmrp metric
show ip dvmrp route
tunnel mode †ip dvmrp default-information
To advertise network 0.0.0.0 to DVMRP neighbors on an interface, use the ip dvmrp default-information interface configuration command. To prevent the advertisement, use the no form of this command.
ip dvmrp default-information {originate | only}
no ip dvmrp default-information {originate | only}Syntax Description
originate
Other routes more specific than 0.0.0.0 can also be advertised.
only
No DVMRP routes other than 0.0.0.0 are advertised.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command should only be used when the router is a neighbor to mrouted version 3.6 machines. The mrouted protocol is a public domain implementation of DVMRP.
You can use the ip dvmrp metric command with the ip dvmrp default-information command to tailor the metric used when advertising the default route 0.0.0.0. By default, metric 1 is used.
Example
The following example configures the router to advertise network 0.0.0.0, in addition to other networks, to DVMRP neighbors:
ip dvmrp default-information originateRelated Command
ip dvmrp metric
To configure the metric associated with a set of destinations for DVMRP reports, use the ip dvmrp metric interface configuration command. To disable this function, use the no form of this command.
ip dvmrp metric metric [list access-list-number] [protocol process-id] | [dvmrp]
no ip dvmrp metric metric [list access-list-number] [protocol process-id] | [dvmrp]Syntax Description
Default
No metric is preconfigured. Only directly connected subnets and networks are advertised to neighboring DVMRP routers.
Command Mode
Interface configuration
Usage Guidelines
When PIM is configured on an interface and DVMRP neighbors are discovered, the router sends DVMRP report messages for directly connected networks. The ip dvmrp metric command enables DVMRP report messages for multicast destinations that match the access list. Usually, the metric for these routes is 1. Under certain circumstances, it may be desirable to tailor the metric used for various unicast routes.
Use the access-list-number argument in conjunction with the protocol process-id arguments to selectively list the destinations learned from a given routing protocol.
To display DVMRP activity, use the debug ip dvmrp command.
Example
The following example connects a PIM cloud to a DVMRP cloud. Access list 1 permits the sending of DVMRP reports to the DVMRP routers advertising all sources in the 198.92.35.0 network with a metric of 1. Access list 2 permits all other destinations, but the metric of 0 means that no DVMRP reports are sent for these destinations.
access-list 1 permit 198.92.35.0 0.0.0.255access-list 1 deny 0.0.0.0 255.255.255.255access-list 2 permit 0.0.0.0 255.255.255.255interface tunnel 0ip dvmrp metric 1 list 1ip dvmrp metric 0 list 2Related Commands
Two daggers (††) indicate that the command is documented in the Debug Command Reference publication.
debug ip dvmrp ††
ip dvmrp accept-filterip dvmrp metric-offset
To change the metrics of advertised DVMRP routes and thus favor or not favor a certain route, use the ip dvmrp metric-offset interface configuration command. To restore the default values, use the no form of this command.
ip dvmrp metric-offset [in | out] increment
no ip dvmrp metric-offsetSyntax Description
Defaults
If neither in nor out is specified, in is the default.
The default for in is 1.
The default for out is 0.Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
Use this command to influence which routes are used, as you prefer. The DVMRP metric is in hop count.
Example
The following example adds 10 to the incoming DVMRP reports:
ip dvmrp metric-offset 10ip dvmrp reject-non-pruners
To configure the router so that it will not peer with a DVMRP neighbor if that neighbor does not support DVMRP pruning or grafting, use the ip dvmrp reject-non-pruners interface configuration command. To disable the feature, use the no form of this command.
ip dvmrp reject-non-pruners
no ip dvmrp reject-non-prunersSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
By default, the router accepts all DVMRP neighbors as peers, regardless of their DVMRP capability or lack thereof.
Use this command to prevent a router from peering with a DVMRP neighbor if that neighbor does not support DVMRP pruning or grafting. If the router receives a DVMRP Probe or Report message without the Prune-Capable flag set, the router logs a syslog message and discards the message.
Note that this command prevents peering with neighbors only. If there are any non-pruning routers multiple hops away (downstream toward potential receivers) that are not rejected, then a non-pruning DVMRP network might still exist.
Example
The following example configures the router not to peer with DVMRP neighbors that do not support pruning or grafting:
ip dvmrp reject-non-prunersip dvmrp routehog-notification
To change the number of DVMRP routes allowed before a syslog warning message is issued, use the ip dvmrp routehog-notification global configuration command. To restore the default value, use the no form of this command.
ip dvmrp routehog-notification route-count
no ip dvmrp routehog-notificationSyntax Description
Default
10,000 routes
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.2.
This command configures how many DVMRP routes are accepted on each interface within an approximate one-minute interval before a syslog message is issued, warning that there might be a route surge occurring. The warning is typically used to detect quickly when people have misconfigured their routers to inject a large number of routes into the MBONE.
The show ip igmp interface command displays a running count of routes. When the count is exceeded, an "*** ALERT ***" is appended to the line.
Example
The following example lowers the threshold to 8000 routes:
ip dvmrp routehog-notification 8000Related Command
ip dvmrp route-limit
To change the limit on the number of DVMRP routes that can be advertised over an interface enabled to run DVMRP, use the ip dvmrp route-limit global configuration command. To configure no limit, use the no form of this command.
ip dvmrp route-limit count
no ip dvmrp route-limitSyntax Description
Default
7000 routes
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
Interfaces enabled to run DVMRP include a DVMRP tunnel, an interface where a DVMRP neighbor has been discovered, or an interface configured to run ip dvmrp unicast-routing.
The ip dvmrp route-limit command is automatically generated to the configuration file when at least one interface is enabled for multicast routing. This command is necessary to prevent misconfigured ip dvmrp metric commands from causing massive route injection into the multicast backbone (MBONE).
Example
The following example changes the limit to 5000 DVMRP routes allowed to be advertised:
ip dvmrp route-limit 5000Related Command
ip dvmrp unicast-routing
To enable DVMRP unicast routing on an interface, use the ip dvmrp unicast-routing interface configuration command. To disable the feature, use the no form of this command.
ip dvmrp unicast-routing
no ip dvmrp unicast-routingSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
Enabling DVMRP unicast routing means that routes in DVMRP Report messages are cached by the router in a DVMRP routing table. When PIM is running, these routes may get preference over routes in the unicast routing table. This allows PIM to run on the MBONE topology when it is different from the unicast topology.
DVMRP unicast routing can run on all interfaces, including GRE tunnels. On DVMRP tunnels, it runs by virtue of doing DVMRP multicast routing. This command does not enable DVMRP multicast routing among Cisco routers. However, if there is a DVMRP-capable multicast router, the Cisco router will do PIM/DVMRP multicast routing interaction.
Example
The following example enables DVMRP unicast routing:
ip dvmrp unicast-routingRelated Command
ip gdp
To enable GDP routing on an interface, use the ip gdp interface configuration command. To disable GDP routing, use the no form of this command.
ip gdp [priority number | reporttime seconds | holdtime seconds]
no ip gdpSyntax Description
Default
priority: 100
reporttime: 5 seconds for broadcast media; 0 for nonbroadcast media
holdtime: 15 secondsCommand Mode
Interface configuration
Usage Guidelines
When enabled on an interface, GDP updates report the primary and secondary IP addresses of that interface.
Example
In the following example, GDP is enabled on Ethernet interface 1 with a report time of 10 seconds, and priority and hold time set to their defaults (because none are specified):
ip gdp reporttime 10ip hello-interval eigrp
To configure the hello interval for the Enhanced IGRP routing process designated by an autonomous system number, use the ip hello-interval eigrp interface configuration command. To restore the default value, use the no form of this command.
ip hello-interval eigrp autonomous-system-number seconds
no ip hello-interval eigrp autonomous-system-number secondsSyntax Description
Default
For low-speed, NBMA networks: 60 seconds
For all other networks: 5 secondsCommand Mode
Interface configuration
Usage Guidelines
The default of 60 seconds applies only to low speed, nonbroadcast, mutiaccess (NBMA) media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command. Note that for the purposes of Enhanced IGRP, Frame Relay and SMDS networks may or may not be considered to be NBMA. These networks are considered NBMA if the interface has not been configured to use physical multicasting; otherwise they are considered not to be NBMA.
Example
The following example sets the hello interval for Ethernet interface 0 to 10 seconds:
interface ethernet 0ip hello-interval eigrp 109 10Related Command
ip hold-time eigrp
To configure the hold time for a particular Enhanced IGRP routing process designated by the autonomous system number, use the ip hold-time eigrp interface configuration command. To restore the default value, use the no form of this command.
ip hold-time eigrp autonomous-system-number seconds
no ip hold-time eigrp autonomous-system-number secondsSyntax Description
Default
For low-speed, NBMA networks: 180 seconds
For all other networks: 15 secondsCommand Mode
Interface configuration
Usage Guidelines
On very congested and large networks, the default hold time might not be sufficient time for all routers to receive hello packets from their neighbors. In this case, you may want to increase the hold time.
We recommend that the hold time be at least three times the hello interval. If a router does not receive a hello packet within the specified hold time, routes through the router are considered unavailable.
Increasing the hold time delays route convergence across the network.
The default of 180 seconds hold time and 60 seconds hello interval apply only to low speed, nonbroadcast, multiaccess (NBMA) media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command.
Example
The following example sets the hold time for Ethernet interface 0 to 40 seconds:
interface ethernet 0ip hold-time eigrp 109 40Related Command
ip igmp access-group
To control the multicast groups that hosts on the subnet serviced by an interface can join, use the ip igmp access-group interface configuration command. To disable groups on an interface, use the no form of this command.
ip igmp access-group access-list-number
no ip igmp access-group access-list-numberSyntax Description
Default
All groups are allowed on an interface.
Command Mode
Interface configuration
Example
In the following example, hosts serviced by Ethernet interface 0 can join the group 225.2.2.2 only:
access-list 1 225.2.2.2 0.0.0.0interface ethernet 0ip igmp access-group 1Related Command
ip igmp join-group
To have the router join a multicast group, use the ip igmp join-group interface configuration command. To cancel membership in a multicast group, use the no form of this command.
ip igmp join-group group-address
no ip igmp join-group group-addressSyntax Description
group-address
Address of the multicast group. This is a multicast IP address in four-part dotted notation.
Default
No multicast group memberships are predefined.
Command Mode
Interface configuration
Usage Guidelines
IP packets that are addressed to the group address are passed to the IP client process in the router.
If all the multicast-capable routers that you administer are members of a multicast group, pinging that group causes all routers to respond. This can be a useful administrative and debugging tool.
Another reason to have a router join a multicast group is when other hosts on the network have a bug in IGRP that prevents them from correctly answering IGMP queries. Having the router join the multicast group causes upstream routers to maintain multicast routing table information for that group and keep the paths for that group active.
Example
In the following example, the router joins multicast group 225.2.2.2:
ip igmp join-group 225.2.2.2Related Commands
A dagger (†) indicates that the command is documented in another chapter.
ip igmp access-group
ping (privileged) †
ping (user) †ip igmp query-interval
To configure the frequency at which the router sends IGMP host-query messages, use the ip igmp query-interval interface configuration command. To return to the default frequency, use the no form of this command.
ip igmp query-interval seconds
no ip igmp query-intervalSyntax Description
seconds
Frequency, in seconds, at which to transmit IGMP host-query messages. The can be a number from 0 to 65535. The default is 60 seconds.
Default
60 seconds
Command Mode
Interface configuration
Usage Guidelines
Multicast routers send host membership query messages (referred to as host-query messages) to discover which multicast groups have members on the router's attached networks. Hosts respond with IGMP report messages indicating that they wish to receive multicast packets for specific groups (that is, indicating that the host wants to become a member of the group). Host-query messages are addresses to the all-hosts multicast group, which has the address 224.0.0.1, and have an IP TTL value of 1.
The designated router for a LAN is the only router that sends IGMP host-query messages. The designated router is elected according to the multicast routing protocol that runs on the LAN.
Note
Example
The following example changes the frequency at which the designated router sends IGMP host-query messages to 2 minutes:
interface tunnel 0ip igmp query-interval 120Related Commands
ip pim query-interval
show ip igmp groupsip irdp
To enable ICMP Router Discovery Protocol (IRDP) processing on an interface, use the ip irdp interface configuration command. To disable IRDP routing, use the no form of this command.
ip irdp [multicast | holdtime seconds | maxadvertinterval seconds | minadvertinterval
seconds | preference number | address address [number]]
no ip irdpSyntax Description
Default
Disabled
When enabled, IRDP uses these defaults:
•
•
•
•
Command Mode
Interface configuration
Usage Guidelines
If you change maxadvertinterval, the other two values also change, so it is important to change maxadvertinterval first before changing either holdtime or minadvertinterval.
The ip irdp multicast command allows for compatibility with Sun Microsystems Solaris, which requires IRDP packets to be sent out as multicasts. Many implementations cannot receive these multicasts; ensure end host ability before using this command.
Example
The following example illustrates how to set the various IRDP processes:
! enable irdp on interface Ethernet 0interface ethernet 0
ip irdp
! send IRDP advertisements to the multicast addressip irdp multicast
! increase router preference from 100 to 50ip irdp preference 50
! set maximum time between advertisements to 400 secsip irdp maxadvertinterval 400
! set minimum time between advertisements to 100 secsip irdp minadvertinterval 100
! advertisements are good for 6000 secondsip irdp holdtime 6000
! proxy-advertise 131.108.14.5 with default router preferenceip irdp address 131.108.14.5
! proxy-advertise 131.108.14.6 with preference of 50ip irdp address 131.108.14.6 50ip local policy route-map
To identify a route map to use for local policy routing, use the ip local policy route-map global configuration command. To disable local policy routing, use the no form of this command.
ip local policy route-map map-tag
no ip local policy route-map map-tagSyntax Description
map-tag
Name of the route map to use for local policy routing. The name must match a map-tag specified by a route-map command.
Default
Packets that are generated by the router are not policy-routed.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
Packets that are generated by the router are not normally policy-routed. However, you can use this command to policy-route such packets. You might enable local policy routing if you want packets originated at the router to take a route other than the obvious shortest path.
The ip local policy route-map command identifies a route map to use for local policy routing. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which packets should be policy-routed. The set commands specify the set actions—the particular policy routing actions to perform if the criteria enforced by the match commands are met. The no ip local policy route-map command deletes the reference to the route map and disables local policy routing.
Example
In the following example, packets with a destination IP address matching that allowed by extended access list 131 are sent to the router at IP address 174.21.3.20:
ip local policy route-map xxx!route-map xxxmatch ip address 131set ip next-hop 174.21.3.20Related Commands
match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop
show ip local policyip mroute
To configure a multicast static route (mroute), use the ip mroute global configuration command. To remove the route, use the no form of this command.
ip mroute source mask [protocol as-number] {rpf-address | type number} [distance]
no ip mroute source mask [protocol as-number] {rpf-address | type number} [distance]Syntax Description
Default
distance: 0
Command Mode
Global configuration
Usage Guidelines
This command allows you to statically configure where multicast sources are located (even though the unicast routing table says something different).
When a source range is specified, the rpf-address applies only to those sources.
Examples
The following example configures all sources via a single interface (in this case, a tunnel):
ip mroute 0.0.0.0 255.255.255.255 tunnel0The following example configures all specific sources within a network number are reachable through 171.68.10.13:
ip mroute 171.69.0.0 255.255.0.0 171.68.10.13The following example causes this multicast static route to take effect if the unicast routes for any given destination go away:
ip mroute 0.0.0.0 255.255.255.255 serial0 200ip mroute-cache
To configure IP multicast fast switching, use the ip mroute-cache interface configuration command. To disable IP multicast fast switching, use the no form of this command.
ip mroute-cache
no ip mroute-cacheSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
If fast switching is disabled on an incoming interface for a multicast routing table entry, the packet will be sent at process level for all interfaces in the outgoing interface list.
If fast switching is disabled on an outgoing interface for a multicast routing table entry, the packet is process level switched for that interface, but might be fast-switched for other interfaces in the outgoing interface list.
When fast switching is enabled (like unicast routing), debug messages are not logged. If you want to log debug messages, disable fast switching.
Example
The following example disables IP multicast fast switching on the interface:
no ip mroute-cacheip multicast rate-limit
To control the rate a sender from the source-list can send to a multicast group in the group-list, use the ip multicast rate-limit interface configuration command. To remove the control, use the no form of this command.
ip multicast rate-limit {in | out} [group-list access-list] [source-list access-list] kbps
no multicast rate-limit {in | out} [group-list access-list] [source-list access-list] kbpsSyntax Description
Default
kbps = 0, meaning that there is no limit on the rate traffic is sent.
Command Mode
Interface configuration
Usage Guidelines
If a router receives a packet and in the last second the user has sent over the limit, the packet is dropped; otherwise, it is forwarded.
Example
In the following example, packets to any group from sources in network 171.69.0.0 will have their packets rate-limited to 64 kilobits per second:
interface serial 0ip multicast rate-limit out group-list 1 source-list 2 64access-list 1 permit 0.0.0.0 255.255.255.255access-list 2 permit 171.69.0.0 0.0.255.255ip multicast-routing
To enable IP multicast routing on the router, use the ip multicast-routing global configuration command. To disable IP multicast routing, use the no form of this command.
ip multicast-routing
no ip multicast-routingSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
When IP multicast routing is disabled, the router does not forward any multicast packets.
Example
The following example enables IP multicast routing on the router:
ip multicast-routingRelated Command
ip multicast ttl-threshold
To configure the time-to-live (TTL) threshold of packets being forwarded out an interface, use the ip multicast ttl-threshold interface configuration command. To return to the default TTL threshold, use the no form of this command.
ip multicast ttl-threshold ttl
no ip multicast ttl-threshold [ttl]Syntax Description
ttl
Time-to-live value, in hops. It can be a value from 0 to 255. The default value is 0, which means that all multicast packets are forwarded out the interface.
Default
0, which means that all multicast packets are forwarded out the interface.
Command Mode
Interface configuration
Usage Guidelines
Only multicast packets with a TTL value greater than the threshold are forwarded out the interface.
You should configure the TTL threshold only on border routers. Conversely, routers on which you configure a TTL threshold value automatically become border routers.
This command replaces the ip multicast-threshold command, which is obsolete.
Example
In the following example, you set the TTL threshold on a border router to 200, which is a very high value. This means that multicast packets must have a TTL greater than 200 in order to be forwarded out this interface. Multicast applications generally set this value well below 200. Therefore, setting a value of 200 means that no packets will be forwarded out the interface.
interface tunnel 0ip multicast ttl-threshold 200ip ospf authentication-key
To assign a password to be used by neighboring routers that are using OSPF's simple password authentication, use the ip ospf authentication-key interface configuration command. To remove a previously assigned OSPF password, use the no form of this command.
ip ospf authentication-key password
no ip ospf authentication-keySyntax Description
password
Any continuous string of characters that can be entered from the keyboard up to 8 bytes in length.
Default
No password is specified.
Command Mode
Interface configuration
Usage Guidelines
The password created by this command is used as a "key" that is inserted directly into the OSPF header when the router originates routing protocol packets. A separate password can be assigned to each network on a per-interface basis. All neighboring routers on the same network must have the same password to be able to exchange OSPF information.
Note
Example
In the following example, the authentication key is enabled with the string yourpass:
ip ospf authentication-key yourpassRelated Command
ip ospf cost
To explicitly specify the cost of sending a packet on an interface, use the ip ospf cost interface configuration command. To reset the path cost to the default value, use the no form of this command.
ip ospf cost cost
no ip costSyntax Description
cost
Unsigned integer value expressed as the link state metric. It can be a value in the range 1 to 65535.
Default
No default cost is predefined.
Command Mode
Interface configuration
Usage Guidelines
You can set the metric manually using this command. Using the bandwidth command changes the link cost as long as this command is not used.
The link state metric is advertised as the link cost in the router's router link advertisement. We do not support type of service (TOS), so you can assign only one cost per interface.
In general, the path cost is calculated using the following formula:
108 ÷ Bandwidth
Using the above formula, the default path costs were calculated as noted in the following list. If these values do not suit your network, you can use your own method of calculating path costs.
•
•
•
•
•
•
•
•
Example
The following example sets the interface cost value to 65:
ip ospf cost 65ip ospf dead-interval
To set how long a router's Hello packets must not have been seen before its neighbors declare the router down, use the ip ospf dead-interval interface configuration command. To return to the default time, use the no form of this command.
ip ospf dead-interval seconds
no ip ospf dead-intervalSyntax Description
seconds
Unsigned integer that specifies the interval in seconds; the value must be the same for all nodes on the network.
Default
Four times the interval set by the ip ospf hello-interval command
Command Mode
Interface configuration
Usage Guidelines
The interval is advertised in the router's Hello packets. This value must be the same for all routers on a specific network.
Example
The following example sets the OSPF dead interval to 60 seconds:
interface ethernet 1
ip ospf dead-interval 60Related Command
ip ospf hello-interval
To specify the interval between Hello packets that the router sends on the interface, use the ip ospf hello-interval interface configuration command. To return to the default time, use the no form of this command.
ip ospf hello-interval seconds
no ip ospf hello-intervalSyntax Description
seconds
Unsigned integer that specifies the interval in seconds. The value must be the same for all nodes on a specific network.
Default
10 seconds
Command Mode
Interface configuration
Usage Guidelines
This value is advertised in the router's Hello packets. The smaller the Hello interval, the faster topological changes will be detected, but more routing traffic will ensue. This value must be the same for all routers on a specific network.
Example
The following example sets the interval between Hello packets to 15 seconds:
interface ethernet 1ip ospf hello-interval 15Related Command
ip ospf message-digest-key
To enable OSPF MD5 authentication, use the ip ospf message-digest-key interface configuration command. To remove an old MD5 key, use the no form of this command.
ip ospf message-digest-key keyid md5 key
no ip ospf message-digest-key keyidSyntax Description
Default
OSPF MD5 authentication is disabled.
Command Mode
Interface configuration
Usage Guidelines
Usually there is one key per interface, which is used to generate authentication information when sending packets and to authenticate incoming packets. The same key identifier on the neighbor router must have the same key value.
The process of changing keys is as follows. Suppose the current configuration is as follows:
interface ethernet 1ip ospf message-digest-key 100 md5 OLDYou change the configuration to the following:
interface ethernet 1ip ospf message-digest-key 101 md5 NEWThe system assumes its neighbors do not have the new key yet, so it begins a rollover process. It sends multiple copies of the same packet, each authenticated by different keys. In this example, the system sends out two copies of the same packet—the first one authenticated by key 100 and the second one authenticated by key 101.
Rollover allows neighboring routers to continue communication while the network administrator is updating them with the new key. Rollover stops once the local system finds that all its neighbors know the new key. The system detects that a neighbor has the new key when it receives packets from the neighbor authenticated by the new key.
After all neighbors have been updated with the new key, the old key should be removed. In this example, you would enter the following:
interface ethernet 1no ip ospf message-digest-key 100Then, only key 101 is used for authentication on Ethernet interface 1.
We recommend that you not keep more than one key per interface. Every time you add a new key, you should remove the old key to prevent the local system from continuing to communicate with a hostile system that knows the old key. Removing the old key also reduces overhead during rollover.
Example
The following example sets a new key 19 with the password 8ry4222:
interface ethernet 1ip ospf message-digest-key 10 md5 xvv560qleip ospf message-digest-key 19 md5 8ry4222Related Command
area authentication
ip ospf name-lookup
To configure OSPF to look up Domain Name System (DNS) names for use in all OSPF show EXEC command displays, use the ip ospf name-lookup global configuration command. To disable this feature, use the no form of this command.
ip ospf name-lookup
no ip ospf name-lookupSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
This feature makes it easier to identify a router because it is displayed by name rather than by its router ID or neighbor ID.
Example
The following example configures OSPF to look up DNS names for use in all OSPF show EXEC command displays:
ip ospf name-lookupSample Display
The following is sample output from the show ip ospf database EXEC command, for example, once you have enabled the DNS name lookup feature.
Router# show ip ospf databaseOSPF Router with id (160.89.41.1) (Autonomous system 109)Router Link States (Area 0.0.0.0)Link ID ADV Router Age Seq# Checksum Link count160.89.41.1 router 381 0x80000003 0x93BB 4160.89.34.2 neon 380 0x80000003 0xD5C8 2Net Link States (Area 0.0.0.0)Link ID ADV Router Age Seq# Checksum160.89.32.1 router 381 0x80000001 0xC117ip ospf network
To configure the OSPF network type to a type other than the default for a given media, use the ip ospf network interface configuration command. To return to the default value, use the no form of this command.
ip ospf network {broadcast | non-broadcast | point-to-multipoint}
no ip ospf networkSyntax Description
broadcast
Sets the network type to broadcast.
non-broadcast
Sets the network type to nonbroadcast.
point-to-multipoint
Sets the network type to point-to-multipoint.
Default
Depends on the network type
Command Mode
Interface configuration
Usage Guidelines
Using this feature, you can configure broadcast networks as nonbroadcast multiaccess networks when, for example, you have routers in your network that do not support multicast addressing. You can also configure nonbroadcast multiaccess networks, such as X.25, Frame Relay, and SMDS, as broadcast networks. This feature saves you from having to configure neighbors.
Configuring nonbroadcast multiaccess networks as either broadcast or nonbroadcast assumes that there are virtual circuits from every router to every router or fully-meshed network. This is not true for some cases, for example, due to cost constraints or when you have only a partially-meshed network. In these cases, you can configure the OSPF network type as a point-to-multipoint network. Routing between two routers that are not directly connected will go through the router that has virtual circuits to both routers. Note that you do not need to configure neighbors when using this feature.
If this command is issued on an interface that does not allow it, it will be ignored.
Example
The following example sets your OSPF network as a broadcast network:
interface serial 0
ip address 160.89.77.17 255.255.255.0ip ospf network broadcastencapsulation frame-relayRelated Commands
A dagger (†) indicates that the command is documented in another chapter.
frame-relay map †
neighbor (OSPF)
x25 map †ip ospf priority
To set the router's priority, which helps determine the designated router for this network, use the ip ospf priority interface configuration command. To return to the default value, use the no form of this command.
ip ospf priority number
no ip ospf prioritySyntax Description
Default
Priority of 1
Command Mode
Interface configuration
Usage Guidelines
When two routers attached to a network both attempt to become the designated router; the one with the higher router priority takes precedence. If there is a tie, the router with the higher router ID takes precedence. A router with a router priority set to zero is ineligible to become the designated router or backup designated router. Router priority is only configured for interfaces to multiaccess networks (in other words, not point-to-point networks).
This priority value is used when you configure OSPF for nonbroadcast networks using the neighbor router configuration command for OSPF.
Example
The following example sets the router priority value to 4:
interface ethernet 0
ip ospf priority 4Related Commands
ip ospf network
neighbor (OSPF)ip ospf retransmit-interval
To specify the time between link state advertisement retransmissions for adjacencies belonging to the interface, use the ip ospf retransmit-interval interface configuration command. To return to the default value, use the no form of this command.
ip ospf retransmit-interval seconds
no ip ospf retransmit-intervalSyntax Description
Default
5 seconds
Command Mode
Interface configuration
Usage Guidelines
When a router sends a link state advertisement (LSA) to its neighbor, it keeps the LSA until it receives back the acknowledgment. If it receives no acknowledgment in seconds, it will retransmit the LSA.
The setting of this parameter should be conservative, or needless retransmission will result. The value should be larger for serial lines and virtual links.
Example
The following example sets the retransmit-interval value to 8 seconds:
interface ethernet 2
ip ospf retransmit-interval 8ip ospf transmit-delay
To set the estimated time it takes to transmit a link state update packet on the interface, use the ip ospf transmit-delay interface configuration command. To return to the default value, use the no form of this command.
ip ospf transmit-delay seconds
no ip ospf transmit-delaySyntax Description
seconds
Time in seconds that it takes to transmit a link state update. It can be an integer in the range is 1 to 65535 seconds. The default is 1 second.
Default
1 second
Command Mode
Interface configuration
Usage Guidelines
Link state advertisements in the update packet must have their age incremented by the amount specified in the seconds argument before transmission. The value assigned should take into account the transmission and propagation delays for the interface.
If the delay is not added before transmission over a link, the time in which the LSA propagates over the link is not considered. This setting has more significance on very low speed links.
Example
The following example sets the retransmit-delay value to 3 seconds:
interface ethernet 0
ip ospf transmit-delay 3ip pim
To enable PIM on an interface, use the ip pim interface configuration command. To disable PIM on the interface, use the no form of this command.
ip pim {dense-mode | sparse-mode}
no ip pim {dense-mode | sparse-mode}Syntax Description
Default
IP multicast routing is disabled on all interfaces.
Command Mode
Interface configuration
Usage Guidelines
Enabling PIM on an interface also enables IGMP operation on that interface. An interface can be configured to be in dense mode or sparse mode. The mode describes how the router populates its multicast routing table and how the router forwards multicast packets it receives from its directly connected LANs. In populating the multicast routing table, dense-mode interfaces are always added to the table. Sparse-mode interfaces are added to the table only when periodic join messages are received from downstream routers or there is a directly connected member on the interface.
Initially, a dense-mode interface forwards multicast packets until the router determines that there are group members or downstream routers, or until a prune message is received from a downstream router. Then, the dense-mode interface will periodically forward multicast packets out the interface until the same conditions occur. Dense mode assumes that there are multicast group members present. Dense-mode routers never send a join message. They do send prune messages as soon as they determine they have no members or downstream PIM routers. A dense-mode interface is subject to multicast flooding by default.
A sparse-mode interface is used for multicast forwarding only if a join message is received from a downstream router or if there are group members directly connected to the interface. Sparse mode assumes that there are no other multicast group members present. When sparse-mode routers want to join the shared path, they periodically send join messages toward the RP. When sparse-mode routers want to join the source path, they periodically send join messages toward the source; they also send periodic prune messages toward to RP to prune the shared path.
Examples
The following commands enables sparse-mode PIM on tunnel interface 0 and sets the address of the RP router to 226.0.0.8:
interface tunnel 0ip pim sparse-modeip pim rp-address 226.0.0.8The following commands enable dense-mode PIM on Ethernet interface 1:
interface ethernet 1ip pim dense-modeRelated Commands
ip multicast-routing
ip pim rp-address
show ip pim interfaceip pim accept-rp
To configure a router to accept Joins or Prunes destined for a specified RP and for a specific list of groups, use the ip pim accept-rp global configuration command. To remove that check, use the no form of this command.
ip pim accept-rp {address | auto-rp} [group-access-list-number]
no ip pim accept-rp {ip-address | auto-rp} [group-access-list-number]Syntax Description
Default
Disabled, so all Join messages and Prune messages are processed.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.2.
This command causes the router to accept only (*,G) Join messages destined for the specified RP address . Additionally, the group address must be in the range specified by the access list.
When address is one of the system's addresses, the system will be the RP only for the specified group range specified by the access list. When the group address is not in the group range, the RP will not accept Join or Register messages and will respond immediately to Registers with Register-Stop messages.
Example
The following example states that the router will accept Join or Prune messages destined for the RP at address 100.1.1.1 for the multicast group 224.2.2.2:
ip pim accept-rp 100.1.1.1 3access-list 3 permit 224.2.2.2Related Command
access-list (standard)
ip pim nbma-mode
To configure a multiaccess WAN interface to be in nonbroadcast, multiaccess mode, use the ip pim nbma-mode interface configuration command. To disable this feature, use the no form of this command.
ip pim nbma-mode
no pim nbma-modeSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
Use this command on Frame Relay, SMDS, or ATM only, especially when these media do not have native multicast available. Do not use this command on multicast-capable LANs such as Ethernet or FDDI.
When this command is configured, each PIM Join message is kept track of in the outgoing interface list of a multicast routing table entry. Therefore, only PIM WAN neighbors that have joined for the group will get packets sent as data link unicasts. This command should only be used when ip pim sparse-mode is configured on the interface. This command is not recommended for LANs that have natural multicast capabilities.
Example
The following example configures an interface to be in nonbroadcast, multiaccess mode:
ip pim nbma-modeRelated Command
ip pim sparse-mode
ip pim query-interval
To configure the frequency of PIM router-query messages, use the ip pim query-interval interface configuration command. To return to the default interval, use the no form of this command.
ip pim query-interval seconds
no ip pim query-interval [seconds]Syntax Description
seconds
Interval, in seconds, at which periodic PIM router-query messages are sent. It can be a number from 1 to 65535. The default is 30 seconds.
Default
30 seconds
Command Mode
Interface configuration
Usage Guidelines
Routers that are configured for IP multicast send PIM router-query messages to determine which router will be the designated router for each LAN segment (subnet). The designated router is responsible for sending IGMP host-query messages to all hosts on the directly connected LAN. When operating in sparse mode, the designated router is responsible for sending source registration messages to the RP. The designated router is the router with the largest IP address.
Example
The following example changes the PIM router-query message interval to 45 seconds:
interface tunnel 0ip pim query-interval 45Related Command
ip pim rp-address
To configure the address of a PIM rendezvous point (RP) for a particular group, use the ip pim rp-address global configuration command. To remove an RP address, use the no form of this command.
ip pim rp-address ip-address [access-list-number]
no ip pim rp-address ip-address [access-list-number]Syntax Description
Default
No PIM RPs are preconfigured.
Command Mode
Global configuration
Usage Guidelines
You must configure the IP address of RPs in leaf routers only. Leaf routers are those routers that are directly connected either to a multicast group member or to a sender of multicast messages.
The RP address is used by first-hop routers to send register packets on behalf of source multicast hosts to the RP. This address is also used by routers on behalf of multicast hosts that want to become members of a group to send join messages towards the RP. The RP must be a PIM router; however, it does not require any special configuration to recognize that it is the RP. Also, RPs are not members of the multicast group; rather, they serve as a "meeting place" for multicast sources and group members.
Choosing the router that will be an RP requires prior coordination between the people who want to be members of the multicast group. You should examine the length of the paths between members and sources. Remember that most multicast members will eventually want to join to the source tree that is the shortest route between the source and the group member.
You can configure a router to use a single RP for more than one group. The conditions specified by the access list determine which groups the RP can be used for. If no access list is configured, the RP is used for all groups.
A PIM router can use multiple RPs.
First-hop routers for multicast sources send register packets to all configured RPs. First-hop routers for multicast group members send join packets to one RP at a time. Once this router begins receiving multicast packets for the group, it will have joined one RP tree. Because the router does not want to receive multiple copies of the same packet, it joins only one RP tree.
Examples
The following example sets the PIM RP address to 198.92.37.33 for all multicast groups:
ip pim rp-address 198.92.37.33The following example sets the PIM RP address to 147.106.6.22 for the multicast group 225.2.2.2 only:
access list 1 225.2.2.2 0.0.0.0ip pim rp-address 147.106.6.22 1Related Commands
A dagger (†) indicates that the command is documented in another chapter.
access-list (extended) †
access-list (standard) †ip policy route-map
To identify a route map to use for policy routing on an interface, use the ip policy route-map interface configuration command. To disable policy routing on the interface, use the no form of this command.
ip policy route-map map-tag
no ip policy route-map map-tagSyntax Description
map-tag
Name of the route map to use for policy routing. Must match a map-tag specified by a route-map command.
Default
No policy routing occurs on the interface.
Command Mode
Interface configuration
Usage Guidelines
You might enable policy routing if you want your packets to take a route other than the obvious shortest path.
The ip policy route-map command identifies a route map to use for policy routing. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which policy routing is allowed for the interface. The set commands specify the set actions—the particular policy routing actions to perform if the criteria enforced by the match commands are met. The no ip policy route-map command deletes the pointer to the route map.
Example
In the following example, packets with the destination IP address of 174.95.16.18 are sent to the router at IP address 174.21.3.20:
interface serial 0ip policy route-map wethersfield!route-map wethersfieldmatch ip address 174.95.16.18set ip next-hop 174.21.3.20Related Commands
match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hopip route
To establish static routes, use the ip route global configuration command. To remove static routes, use the no form of this command.
ip route network [mask] {address | interface} [distance]
no ip routeSyntax Description
Default
No static routes are established.
Command Mode
Global configuration
Usage Guidelines
A static route is appropriate when the router cannot dynamically build a route to the destination.
If you specify an administrative distance, you are flagging a static route that can be overridden by dynamic information. For example, IGRP-derived routes have a default administrative distance of 100. To have a static route that would be overridden by an IGRP dynamic route, specify an administrative distance greater than 100. Static routes have a default administrative distance of 1.
Static routes that point to an interface will be advertised via RIP, IGRP, and other dynamic routing protocols, regardless of whether redistribute static commands were specified for those routing protocols. This is because static routes that point to an interface are considered in the routing table to be connected and hence lose their static nature. However, if you define a static route to an interface that is not one of the networks defined in a network command, no dynamic routing protocols will advertise the route unless a redistribute static command is specified for these protocols.
Examples
In the following example, an administrative distance of 110 was chosen. In this case, packets for network 10.0.0.0 will be routed through to the router at 131.108.3.4 if dynamic information with administrative distance less than 110 is not available.
ip route 10.0.0.0 255.0.0.0 131.108.3.4 110
In the following example, packets for network 131.108.0.0 will be routed to the router at 131.108.6.6:
ip route 131.108.0.0 255.255.0.0 131.108.6.6ip router isis
To configure an IS-IS routing process for IP on an interface, use the ip router isis interface configuration command. To disable IS-IS for IP, use the no form of this command.
ip router isis [tag]
no ip router isis [tag]Syntax Description
Default
No routing processes are specified.
Command Mode
Interface configuration
Example
The following example specifies IS-IS as an IP routing protocol for a process named Finance, and specifies that the Finance process will be routed on interfaces Ethernet 0 and serial 0:
router isis Financeinterface Ethernet 0ip router isis Financeinterface serial 0ip router isis FinanceRelated Command
ip sd listen
To enable the router to listen to session directory advertisements, use the ip sd listen interface configuration command. To disable this feature, use the no form of this command.
ip sd listen
no ip sd listenSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
Session Directory Protocol is a multicast application for creating desktop conferencing sessions. It creates group addresses and allows the user to specify the scope of the group and whether audio, video, or whiteboard applications will be invoked when others open the session.
The ip sd listen command merely enables the router to listen to session directory advertisements. The router joins the default session directory group (group 224.2.127.255) on the interface. Use this command to get contact information.
Example
The following example enables the router to listen to session directory advertisements:
ip sd listenRelated Commands
ip split-horizon
To enable the split-horizon mechanism, use the ip split-horizon interface configuration command. To disable the split-horizon mechanism, use the no form of this command.
ip split-horizon
no ip split-horizonSyntax Description
This command has no arguments or keywords.
Default
Varies with media
Command Mode
Interface configuration
Usage Guidelines
For all interfaces except those for which either Frame Relay or SMDS encapsulation is enabled, the default condition for this command is ip split-horizon; in other words, the split horizon feature is active. If the interface configuration includes either the encapsulation frame-relay or encapsulation smds commands, then the default is for split horizon to be disabled. Split horizon is not disabled by default for interfaces using any of the X.25 encapsulations.
Note
If split horizon has been disabled on an interface and you wish to enable it, use the ip split-horizon command to restore the split horizon mechanism.
Note
Example
The following simple example disables split horizon on a serial link. The serial link is connected to an X.25 network:
interface serial 0encapsulation x25no ip split-horizonRelated Commands
ip split-horizon eigrp
neighborip split-horizon eigrp
To enable Enhanced IGRP split horizon, use the ip split-horizon eigrp interface configuration command. To disable split horizon, use the no form of this command.
ip split-horizon eigrp autonomous-system-number
no ip split-horizon eigrp autonomous-system-numberSyntax Description
Default
Enabled
Command Mode
Interface configuration
Usage Guidelines
For networks that include links over X.25 PSNs, you can use the neighbor router configuration command to defeat the split horizon feature. As an alternative, you can explicitly specify the no ip split-horizon eigrp command in your configuration. However, if you do so, you must similarly disable split horizon for all routers in any relevant multicast groups on that network.
In general, it is recommended that you not change the default state of split horizon unless you are certain that your application requires the change in order to properly advertise routes. Remember that if split horizon is disabled on a serial interface and that interface is attached to a packet-switched network, you must disable split horizon for all routers in any relevant multicast groups on that network.
Example
The following example disables split horizon on a serial link connected to an X.25 network:
interface serial 0encapsulation x25no ip split-horizon eigrpRelated Commands
ip split-horizon
neighborip summary-address eigrp
To configure a summary aggregate address for a specified interface, use the ip summary-address eigrp interface configuration command. To disable a configuration, use the no form of this command.
ip summary-address eigrp autonomous-system-number address mask
no ip summary-address eigrp autonomous-system-number address maskSyntax Description
autonomous-system-number
Autonomous system number.
address
IP summary aggregate address to apply to an interface.
mask
Subnet mask.
Default
No summary aggregate addresses are predefined.
Command Mode
Interface configuration
Usage Guidelines
Enhanced IGRP summary routes are given an administrative distance value of 5. You cannot configure this value.
Example
The following example sets the IP summary aggregate address for Ethernet interface 0:
interface ethernet 0ip summary-address eigrp 109 192.1.0.0 255.255.0.0Related Command
isis circuit-type
To configure the type of adjacency, use the isis circuit-type interface configuration command. To reset the circuit type to Level l and Level 2, use the no form of this command.
isis circuit-type {level-1 | level-1-2 | level-2-only}
no isis circuit-typeSyntax Description
Default
A Level 1 and Level 2 adjacency is established.
Command Mode
Interface configuration
Example
In the following example, a router is configured to require Level 1 adjacency if there is at least one area address in common between this system and its neighbors:
ip router isisinterface serial 0isis circuit-type level-1isis csnp-interval
To configure the IS-IS complete sequence number PDUs (CSNP) interval, use the isis csnp-interval interface configuration command. To restore the default value, use the no form of this command.
isis csnp-interval seconds {level-1 | level-2}
no isis csnp-interval {level-1 | level-2}Syntax Description
Default
10 seconds
Command Mode
Interface configuration
Usage Guidelines
This command only applies for the designated router (DR) for a specified interface. Only DRs send CSNP packets in order to maintain database synchronization. The CSNP interval can be configured independently for Level 1 and Level 2. This feature does not apply to serial point-to-point interfaces. It does apply to WAN connections if the WAN is viewed as a multiaccess meshed network.
Example
In the following example, serial interface 0 is configured for transmitting CSN PDUs every 5 seconds. The router is configured to act as a station router.
interface serial 0isis csnp-interval 5 level-1isis hello-interval
To specify the length of time between Hello packets that the router sends, use the isis hello-interval interface configuration command. To restore the default value, use the no form of this command.
isis hello-interval seconds {level-1 | level-2}
no isis hello-interval {level-1 | level-2}Syntax Description
Default
10 seconds
Command Mode
Interface configuration
Usage Guidelines
The Hello interval can be configured independently for Level 1 and Level 2, except on serial point-to-point interfaces. (Because there is only a single type of Hello packet sent on serial links, it is independent of Level 1 or Level 2.) The level-1 and level-2 keywords are used on X.25, SMDS, and Frame Relay multiaccess networks.
Example
In the following example, serial interface 0 is configured to advertise Hello packets every 5 seconds. The router is configured to act as a station router. This will cause more traffic than configuring a longer interval, but topological changes will be detected faster.
interface serial 0isis hello-interval 5 level-1isis metric
To configure the metric for an interface, use the isis metric interface configuration command. To restore the default metric value, use the no form of this command.
isis metric default-metric [delay-metric [expense-metric [error-metric]]] {level-1 | level-2}
no isis metric {level-1 | level-2}Syntax Description
Default
default-metric = 10
Command Mode
Interface configuration
Usage Guidelines
Specifying the level-1 or level-2 keywords resets the metric only for Level 1 or Level 2 routing, respectively.
Example
In the following example, serial interface 0 is configured for a default link-state metric cost of 15 for Level 1:
interface serial 0isis metric 15 level-1Related Commands
default-information
redistributeisis password
To configure the authentication password for an interface, use the isis password interface configuration command. To disable authentication for IS-IS, use the no form of this command.
isis password password {level-1 | level-2}
no isis password {level-1 | level-2}Syntax Description
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
Different passwords can be assigned for different routing levels using the level-1 and level-2 keyword arguments.
Specifying the level-1 or level-2 keywords disables the password only for Level 1 or Level 2 routing, respectively. If no keyword is specified, the default is level-1.
Example
The following example configures a password for serial interface 0 at Level 1:
interface serial 0isis password frank level-1isis priority
To configure the priority of designated routers, use the isis priority interface configuration command. To reset the default priority, use the no form of this command.
isis priority value {level-1 | level-2}
no isis priority {level-1 | level-2}Syntax Description
Default
Priority of 64
Command Mode
Interface configuration
Usage Guidelines
Priorities can be configured for Level 1 and Level 2 independently. Specifying the level-1 or
level-2 keywords resets priority only for Level 1 or Level 2 routing, respectively.Example
The following example shows Level 1 routing given priority by setting the priority level to 50:
interface serial 0isis priority 50 level-1isis retransmit-interval
To configure the time between retransmission of IS-IS link-state PDU (LSP) retransmission for point-to-point links, use the isis retransmit-interval interface configuration command. To restore the default value, use the no form of this command.
isis retransmit-interval seconds
no isis retransmit-interval secondsSyntax Description
Default
5 seconds
Command Mode
Interface configuration
Usage Guidelines
The setting of the seconds argument should be conservative, or needless retransmission will result. The value should be larger for serial lines and virtual links.
Example
The following example configures serial interface 0 for retransmission of IS-IS LSP every 10 seconds for a large serial line:
interface serial 0isis retransmit-interval 10Related Commands
A dagger (†) indicates that the command is documented in another chapter.
encapsulation ppp †
frame-relay keepalive †
smds dxi †is-type
To configure the IS-IS level at which the router operates, use the is-type router configuration command. To reset the default value, use the no form of this command.
is-type {level-1 | level-1-2 | level-2-only}
no is-type {level-1 | level-1-2 | level-2-only}Syntax Description
level-1
Router acts as a station router.
level-1-2
Router acts as both a station router and an area router.
level-2-only
Router acts as an area router only.
Default
Router acts as both a station router and an area router.
Command Mode
Router configuration
Example
The following example specifies an area router:
router isisis-type level-2-onlymatch as-path
To match a BGP autonomous system path access list, use the match as-path route-map configuration command. To remove a path list entry, the no form of this command.
match as-path path-list-number
no match as-path path-list-numberSyntax Description
Default
No path lists are defined.
Command Mode
Route-map configuration
Usage Guidelines
The values set by the match and set commands override global values. For example, the weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
The implemented weight is based on the first matched autonomous system path.
Example
In the following example, the autonomous system path is set to match BGP autonomous system path access list 20:
route-map igp2bgpmatch as-path 20Related Commands
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmatch community-list
To match a BGP community, use the match community-list route-map configuration command. To remove the community list entry, use the no form of this command.
match community-list community-list-number [exact]
no match community-list community-list-number [exact]Syntax Description
Default
No community list is defined.
Command Mode
Route-map configuration
Usage Guidelines
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
Matching based on community list is one of the types of match clauses applicable to BGP.
Examples
In the following example, the routes that match community list 1 will have the weight set to 100. Any route that has community 109 will have the weight set to 100.
ip community-list 1 permit 109!route-map set_weightmatch community-list 1set weight 100In the following example, the routes that match community list 1 will have the weight set to 200. Any route that has community 109 alone will have the weight set to 200.
ip community-list 1 permit 109!route-map set_weightmatch community-list 1 exactset weight 200Related Commands
ip community-list
route-map
set weightmatch interface
To distribute any routes that have their next hop out one of the interfaces specified, use the match interface route-map configuration command. To remove the match interface entry, use the no form of this command.
match interface type number...type number
no match interface type number...type numberSyntax Description
Default
No match interfaces are defined.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
Example
In the following example, routes that have their next hop out Ethernet interface 0 will be distributed:
route-map namematch interface ethernet 0Related Commands
match as-path
match community-list
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmatch ip address
To distribute any routes that have a destination network number address that is permitted by a standard access list, or to perform policy routing on packets, use the match ip address route-map configuration command. To remove the match ip address entry, use the no form of this command.
match ip address access-list-number...access-list-number
no match ip address access-list-number...access-list-numberSyntax Description
access-list-number
Number of an access list. It can be an integer from 1 through 99. It can be an extended access list for policy routing.
Default
No access list numbers are specified.
Command Mode
Route-map configuration
Usage Guidelines
Use route maps to redistribute routes or to subject packets to policy routing. Both purposes are described in this section.
•
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The related match commands are listed in the section " Related Commands for Redistribution." The match commands can be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
When you are passing routes through a route map, a route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
•
Another purpose of route maps is to enable policy routing. Use the ip policy route-map interface configuration command, in addition to the route-map global configuration command, and the match and set route-map configuration commands to define the conditions for policy routing packets. Each route-map command has a list of match and set commands associated with it. The related match and set commands are listed in the section " Related Commands for Policy Routing." The match commands specify the match criteria—the conditions under which policy routing occurs. The set commands specify the set actions—the particular routing actions to perform if the criteria enforced by the match commands are met. You might want to policy route packets based on their source, for example, using an access list.
Examples
In the following example, routes that have addresses specified by access list numbers 5 and 80 will be distributed:
route-map namematch ip address 5 80In the following policy routing example, packets that have addresses specified by access list numbers 6 and 25 will be routed to Ethernet interface 0:
interface serial 0ip policy route-map chicago!route-map chicagomatch ip address 6 25set interface ethernet 0Related Commands for Redistribution
match as-path
match community-list
match interface
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightRelated Commands for Policy Routing
ip policy route-map
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hopmatch ip next-hop
To redistribute any routes that have a next-hop router address passed by one of the access lists specified, use the match ip next-hop route-map configuration command. To remove the next-hop entry, use the no form of this command.
match ip next-hop access-list-number...access-list-number
no match ip next-hop access-list-number...access-list-numberSyntax Description
Default
Routes are distributed freely, without being required to match a next-hop address.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
Example
In the following example, routes that have a next-hop router address passed by access list 5 or 80 will be distributed:
route-map namematch ip next-hop 5 80Related Commands
match as-path
match community-list
match interface
match ip address
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmatch ip route-source
To redistribute routes that have been advertised by routers at the address specified by the access lists, use the match ip route-source route-map configuration command. To remove the route-source entry, use the no form of this command.
match ip route-source access-list-number...access-list-number
no match ip route-source access-list-number...access-list-numberSyntax Description
Default
No filtering on route source.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria— the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.
There are situations in which a route's next hop and source router address are not the same.
Example
In the following example, routes that have been advertised by routers at the addresses specified by access lists 5 and 80 will be distributed:
route-map namematch ip route-source 5 80Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmatch length
To base policy routing on the Level 3 length of a packet, use the match length route-map configuration command. To remove the entry, use the no form of this command.
match length min max
no match length min maxSyntax Description
Default
No policy routing on the length of a packet.
Command Mode
Route-map configuration
Usage Guidelines
Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which policy routing occurs. The set commands specify the set actions—the particular routing actions to perform if the criteria enforced by the match commands are met.
The match route-map configuration command has multiple formats. The match commands can be given in any order, and all match commands must "pass" to cause the packet to be routed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
You might want to base your policy routing on the length of packets so that your interactive traffic and bulk traffic are directed to different routers.
Example
In the following example, packets 3 to 200 bytes long, inclusive, will be routed to FDDI interface 0.
interface serial 0ip policy route-map interactive!route-map interactivematch length 3 200set interface fddi 0Related Commands
ip policy route-map
match ip address
route-map
set default interface
set interface
set ip default next-hop
set ip next-hopmatch metric
To redistribute routes with the metric specified, use the match metric route-map configuration command. To remove the entry, use the no form of this command.
match metric metric-value
no match metric metric-valueSyntax Description
metric-value
Route metric, which can be an IGRP five-part metric. It is a metric value from 0 through 4294967295.
Default
No filtering on a metric value.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.
Example
In the following example, routes with the metric 5 will be redistributed.
route-map namematch metric 5Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmatch route-type
To redistribute routes of the specified type, use the match route-type route-map configuration command. To remove the route-type entry, use the no form of this command.
match route-type {local | internal | external [type-1 | type-2] | level-1 | level-2}
no match route-type {local | internal | external [type-1 | type-2] | level-1 | level-2}Syntax Description
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.
Example
In the following example, internal routes will be redistributed:
route-map namematch route-type internalRelated Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmatch tag
To redistribute routes in the routing table that match the specified tags, use the match tag route-map configuration command. To remove the tag entry, use the no form of this command.
match tag tag-value...tag-value
no match tag tag-value...tag-valueSyntax Description
Default
No match tag values are defined.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.
Example
In the following example, routes stored in the routing table with tag 5 will be redistributed:
route-map namematch tag 5Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightmaximum-paths
To control the maximum number of parallel routes an IP routing protocol can support, use the maximum-paths router configuration command. To restore the default value, use the no form of this command.
maximum-paths maximum
no maximum-pathsSyntax Description
maximum
Maximum number of parallel routes an IP routing protocol installs in a routing table, in the range 1 to 6. However, BGP supports only one path.
Defaults
The default for BGP is 1 path. The default for all other IP routing protocols is 4 paths.
Command Mode
Router configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
Example
The following example allows a maximum of 2 paths to a destination:
maximum-paths 2mbranch
To trace a branch of a multicast tree for a specific group, use the mbranch EXEC command.
mbranch {group-address | group-name} branch [ttl]
Syntax Description
Command Mode
EXEC
Usage Guidelines
The mbranch command sends multicast IGMP trace request packets to the specified branch router. It displays information about the branch starting with the local (requesting) router and ending with the branch router. This is considered to be the forward direction.
The information returned shows how a multicast packet sourced by this router will be forwarded by each router on the path to the router with the branch address.
The router with the address branch-address is the only router that responds to the trace request packets. The response is unicast to the source.
It is important to specify a value for the ttl argument if you are tracing through a router on which a multicast threshold has been set with the ip multicast ttl-threshold interface configuration command.
Sample Display
The following is sample output from the mbranch command. This trace is between the same routers as shown in the example for the mbranch command. Note the order of responses. Also note that the outgoing interface list is the same.
PIM2# mbranch 224.0.255.2 198.92.118.2Type escape sequence to abort.Tracing route to group CBONE-WB (224.0.255.2) to 198.92.118.2Response from 10.17.118.10, 76 msec1 PIM9 (10.1.22.9) <- PIM2 (10.1.37.2)Interface list: 131.108.62.0/24 131.108.22.0/24 10.7.0.0/162 PIM-CR (131.108.62.18) <- PIM9 (131.108.62.52)Interface list: 131.108.20.0/24 131.108.53.0/24 131.108.50.0/2410.16.0.0/16 10.17.0.0/163 10.17.118.10 <- 10.17.20.31Interface list: 198.92.118.0/26 198.92.118.192/26The mbranch command is interactive if you specify only the word mbranch. The following output shows sample responses to the system prompts:
Router# mbranchTarget IP group address or name:224.0.255.1Target IP router address or name:sj-eng-f2Ttl [30]:10Source address or name:<CR>Interface:ethernet0Type escape sequence to abort.Tracing route to group cbone-audio.cisco.com (224.0.255.1) to 171.69.4.139Response from sj-eng-f2.cisco.com (171.69.4.139), 4 msec1 sj-eng-cc2.cisco.com (171.69.121.2)<- 0.0.0.0Interface list: 171.69.4.0/242 sj-eng-f2.cisco.com (171.69.4.139)<- sj-eng-cc2.cisco.com (171.69.4.135)Interface list: 171.69.60.128/26describes the fields shown in the first display.
Table 19-3 Mbranch Field Descriptions
Related Commands
ip multicast ttl-threshold
mrbranchmetric holddown
To keep new IGRP routing information from being used for a certain period of time, use the metric holddown router configuration command. To disable this feature, use the no form of this command.
metric holddown
no metric holddownSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
Holddown keeps new routing information from being used for a certain period of time. This can prevent routing loops caused by slow convergence. It is sometimes advantageous to disable holddown to increase the network's ability to quickly respond to topology changes; this command provides this function.
Use the metric holddown command if other routers within the IGRP autonomous system are not configured with no metric holddown. If all routers are not configured the same way, you increase the possibility of routing loops.
Example
The following example disables metric holddown:
router igrp 15network 131.108.0.0network 192.31.7.0no metric holddownRelated Commands
metric maximum-hops
metric weights
timers basic (EGP, RIP, IGRP)metric maximum-hops
To have the IP routing software to advertise as unreachable those routes with a hop count higher than is specified by the command (IGRP only), use the metric maximum-hops router configuration command. To reset the value to the default, use the no form of this command.
metric maximum-hops hops
no metric maximum-hops hopsSyntax Description
hops
Maximum hop count (in decimal). The default value is 100 hops; the maximum number of hops that can be specified is 255.
Default
100 hops
Command Mode
Router configuration
Usage Guidelines
This command provides a safety mechanism that breaks any potential count-to-infinity problems. It causes the IP routing software to advertise as unreachable routes with a hop count greater than the value assigned to the hops argument.
Example
In the following example, a router in autonomous system 71 attached to network 15.0.0.0 wants a maximum hop count of 200, doubling the default. The network administrators decided to do this because they have a complex WAN that can generate a large hop count under normal (nonlooping) operations.
router igrp 71network 15.0.0.0metric maximum-hops 200Related Commands
metric holddown
metric weightsmetric weights
To allow the tuning of the IGRP or Enhanced IGRP metric calculations, use the metric weights router configuration command. To reset the values to their defaults, use the no form of this command.
metric weights tos k1 k2 k3 k4 k5
no metric weightsSyntax Description
tos
Type of service. Currently, it must always be zero.
k1-k5
Constants that convert an IGRP or enhanced IGRP metric vector into a scalar quantity.
Default
tos: 0
k1: 1
k2: 0
k3: 1
k4: 0
k5: 0Command Mode
Router configuration
Usage Guidelines
Use this command to alter the default behavior of IGRP routing and metric computation and allow the tuning of the IGRP metric calculation for a particular type of service (TOS).
If k5 equals 0, the composite IGRP or enhanced IGRP metric is computed according to the following formula:
metric = [k1 * bandwidth + (k2 * bandwidth)/(256 - load) + k3 * delay]If k5 does not equal zero, an additional operation is done:
metric = metric * [k5 / (reliability + k4)]Bandwidth is inverse minimum bandwidth of the path in bits per second scaled by a factor of 2.56 ¥ 1012. The range is from a 1200-bps line to 10 terabits per second.
Delay is in units of 10 microseconds. This gives a range of 10 microseconds to 168 seconds. A delay of all ones indicates that the network is unreachable.
The delay parameter is stored in a 32-bit field, in increments of 39.1 nanoseconds. This gives a range of 1 (39.1 nanoseconds) to hexadecimal FFFFFFFF (decimal 4,294,967,040 nanoseconds). A delay of all ones (that is, a delay of hexadecimal FFFFFFFF) indicates that the network is unreachable.
lists the default values used for several common media.
Table 19-4 Bandwidth Values by Media Type
Reliability is given as a fraction of 255. That is, 255 is 100 percent reliability or a perfectly stable link.
Load is given as a fraction of 255. A load of 255 indicates a completely saturated link.
Example
The following example sets the metric weights to slightly different values than the defaults:
router igrp 109network 131.108.0.0metric weights 0 2 0 2 0 0Related Commands
A dagger (†) indicates that the command is documented in another chapter.
bandwidth †
delay †
metric holddown
metric maximum-hopsmrbranch
To trace a branch of a multicast tree for a group in the reverse direction, use the mrbranch EXEC command.
mrbranch {group-address | group-name} branch-address [ttl]
Syntax Description
Command Mode
EXEC
Usage Guidelines
The mrbranch command sends trace request packets to the specified branch router. Queries are sent recursively to all the routers in the branch. This command displays information about the branch starting with the router farthest away and working towards the requesting router. This is considered to be the reverse direction.
The information returned shows how a multicast packet sourced by this router will be forwarded by each router along the branch.
The router with the address branch-address responds to the trace request packets. The requesting router then sends a query to the router that is the first router's RPF neighbor. Both the request and response packets have unicast addresses.
The number of packets generated by this command is two times the number of routers between the source router and the specified branch router.
Sample Output
The following is sample output from the mrbranch command. This example is between the same router as shown in the mbranch command. Note the order of the responses. Also note that the outgoing interface list is the same.
PIM2# mrbranch 224.0.255.2 10.17.118.10Type escape sequence to abort.Tracing route to group CBONE-WB (224.0.255.2) from 10.17.118.10Response from 10.17.118.10, 68 msec1 10.17.118.10 <- 10.17.20.31Interface list: 198.92.118.0/26 198.92.118.192/26Response from PIM-CR (131.108.62.18), 12 msec1 PIM-CR (131.108.62.18) <- PIM9 (131.108.62.52)Interface list: 131.108.20.0/24 131.108.53.0/24 131.108.50.0/2410.16.0.0/16 10.17.0.0/16Response from PIM9 (131.108.62.52), 8 msec1 PIM9 (131.108.62.52) <- PIM2 (10.1.37.2)Interface list: 131.108.22.0/24 131.108.62.0/24 10.7.0.0/16The mrbranch command is interactive if you specify only the word mrbranch. The following output shows sample responses to the system prompts:
Router# mrbranchTarget IP group address or name:224.0.255.1Target IP router address or name:sj-eng-f2Ttl [30]:10Source address or name:<CR>Interface:ethernet0Type escape sequence to abort.Tracing route to group cbone-audio.cisco.com (224.0.255.1) to 171.69.4.139Response from sj-eng-f2.cisco.com (171.69.4.139), 4 msec1 sj-eng-f2.cisco.com (171.69.4.139)<- sj-eng-cc2.cisco.com (171.69.4.135)Interface list: 171.69.60.128/26Response from sj-eng-f2.cisco.com (171.69.121.2), 4 msec1 sj-eng-cc2.cisco.com (171.69.121.2)<- 0.0.0.0Interface list: 171.69.4.0/24describes the fields shown in the display.
Table 19-5 Mrbranch Field Descriptions
Related Commands
neighbor (EGP, IGRP, RIP)
To define a neighboring router with which to exchange routing information, use this form of the neighbor router configuration command. To remove an entry, use the no form of this command.
neighbor ip-address
no neighbor ip-addressSyntax Description
Default
No neighboring routers are defined.
Command Mode
Router configuration
Usage Guidelines
For exterior routing protocol EGP, this command specifies routing peers. For normally broadcast protocols such as IGRP or RIP, this command permits the point-to-point (nonbroadcast) exchange of routing information. When used in combination with the passive-interface router configuration command, routing information can be exchanged between a subset of routers on a LAN.
Multiple neighbor commands can be used to specify additional neighbors or peers.
OSPF has its own version of the neighbor command. See the neighbor (OSPF) command page in this chapter.
Examples
The following example establishes an EGP neighbor:
autonomous-system 109router egp 110neighbor 131.108.1.1
In the following example, IGRP updates are sent to all interfaces on network 131.108.0.0 except interface Ethernet 1. However, in this case a neighbor router configuration command is included. This command permits the sending of routing updates to specific neighbors. One copy of the routing update is generated per neighbor.
router igrp 109network 131.108.0.0passive-interface ethernet 1neighbor 131.108.20.4Related Command
neighbor (OSPF)
To configure OSPF routers interconnecting to nonbroadcast networks, use this form of the neighbor router configuration command. To remove a configuration, use the no form of this command.
neighbor ip-address [priority number] [poll-interval seconds]
no neighbor ip-address [priority number] [poll-interval seconds]Syntax Description
Default
No configuration is specified.
Command Mode
Router configuration
Usage Guidelines
X.25 and Frame Relay provide an optional broadcast capability that can be configured in the map to allow OSPF to run as a broadcast network. At the OSPF level you can configure the router as a broadcast network. See the x25 map and frame-relay map commands in "X.25 Commands" and "Frame Relay Commands" chapters, respectively, for more detail.
One neighbor entry must be included in the router's configuration for each known nonbroadcast network neighbor. The neighbor address has to be on the primary address of the interface.
If a neighboring router has become inactive (Hello packets have not been seen for the Router Dead Interval period), it may still be necessary to send Hello packets to the dead neighbor. These Hello packets will be sent at a reduced rate called Poll Interval.
When the router first starts up, it sends only Hello packets to those routers with non-zero priority, that is, routers which are eligible to become designated routers (DR) and backup designated routers (BDR). After DR and BDR are selected, DR and BDR will then start sending Hello packets to all neighbors in order to form adjacencies.
Example
The following example declares a router at address 131.108.3.4 on a nonbroadcast network, with a priority of 1 and a poll-interval of 180:
router ospf
neighbor 131.108.3.4 priority 1 poll-interval 180Related Command
neighbor advertisement-interval
To set the minimum interval between the sending of BGP routing updates, use the neighbor advertisement-interval router configuration command. To remove an entry, use the no form of this command.
neighbor {ip-address | peer-group-name} advertisement-interval seconds
no neighbor {ip-address | peer-group-name} advertisement-interval secondsSyntax Description
ip-address
Neighbor's IP address.
peer-group-name
Name of a BGP peer group.
seconds
Time in seconds. Integer from 0 through 600.
Default
30 seconds for external peers and 5 seconds for internal peers.
Command Mode
Router configuration
Usage Guidelines
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configued with this command.
Example
In the following example, the minimum time between sending BGP routing updates is set to 10 seconds:
router bgp 5neighbor 4.4.4.4 advertisement-interval 10Related Command
neighbor peer-group (creating)
neighbor any
To control how neighbor entries are added to the routing table for both EGP and BGP, use the neighbor any router configuration command. To remove a configuration, use the no form of this command.
neighbor any [access-list-number]
no neighbor any [access-list-number]Syntax Description
Default
No configuration is specified.
Command Mode
Router configuration
Example
In the following example, only neighbors permitted by access list 1 are allowed to peer with the local router:
access-list 1 permit 10.0.0.0 0.255.255.255! global access list assignmentrouter egp 0neighbor any 1Related Commands
A dagger (†) indicates that the command is documented in another chapter.
access-list (standard) †
neighbor any third-party
router egp 0neighbor any third-party
To configure an EGP process that determines which neighbors are treated as the next hop in EGP advertisements, use the neighbor any third-party router configuration command. To remove a configuration, use the no form of this command.
neighbor any third-party ip-address [internal | external]
no neighbor any third-party ip-address [internal | external]Syntax Description
Default
No EGP process is configured.
Command Mode
Router configuration
Example
The following example specifies the particular neighbors that an EGP process will view as peers:
access-list 2 permit 10.0.0.0 0.255.255.255! global access list assignmentrouter egp 0neighbor any 2neighbor any third-party 10.1.1.1Related Commands
neighbor configure-neighbors
To have the router treat temporary neighbors that have been accepted by a template as if they had been configured manually, use the neighbor configure-neighbors router configuration command. To restore the default, use the no form of this command.
neighbor template-name configure-neighbors
no neighbor template-name configure-neighborsSyntax Description
template-name
User-selectable designation that identifies a particular template. This can be an arbitrary word.
Default
New neighbors are treated as temporary.
Command Mode
Router configuration
Usage Guidelines
Under normal circumstances, neighbors that are allowed to connect to the router because you had configured a template are treated as temporary. When a temporary neighbor disconnects, the local router will not try to actively reestablish a connection with it. In addition, information about temporary neighbors will not show up in the router configuration (write terminal).
When configure-neighbors is enabled on a particular template, any neighbor accepted by that template will be treated as if it had been manually configured. These neighbors will show up in write terminal displays and will be written to the nonvolatile configuration if a write memory command is issued.
Example
In the following example, any BGP speaker matching access list 7 can connect to the router and exchange information. Any neighbor that connects will be treated as if it had been manually configured.
access-list 7 permit 168.89.3.0 0.0.0.255neighbor internal-ethernet neighbor-list 7neighbor internal-ethernet configure-neighborsRelated Command
neighbor default-originate
To allow a BGP speaker (the local router) to send the default route 0.0.0.0 to a neighbor for use as a default route, use the neighbor default-originate router configuration command. To remove the default route, use the no form of this command.
neighbor {ip-address | peer-group-name} default-originate [route-map map-name]
no neighbor {ip-address | peer-group-name} default-originate [route-map map-name]Syntax Description
ip-address
Neighbor's IP address.
peer-group-name
Name of a BGP peer group.
map-name
(Optional) Name of the route map. The route map allows route 0.0.0.0 to be injected conditionally.
Default
No default route is sent to the neighbor.
Command Mode
Router configuration
Usage Guidelines
This command does not require the presence of 0.0.0.0 in the local router. When used with a route map, the default route 0.0.0.0 is injected if the route map contains a match ip address clause and there is a route that matches the IP access list exactly. The route map can contain other match clauses also.
Examples
In the following example, the local router injects route 0.0.0.0 to the neighbor 160.89.2.3 unconditionally:
router bgp 109network 160.89.0.0neighbor 160.89.2.3 remote-as 200neighbor 160.89.2.3 default-originateIn the following example, the local router injects route 0.0.0.0 to the neighbor 160.89.2.3 only if there is a route to 198.92.68.0:
router bgp 109network 160.89.0.0neighbor 160.89.2.3 remote-as 200neighbor 160.89.2.3 default-originate route-map default-map!route-map default-map 10 permitmatch ip address 1!access-list 1 permit 198.92.68.0neighbor distribute-list
To distribute BGP neighbor information as specified in an access list, use the neighbor distribute-list router configuration command. To remove an entry, use the no form of this command.
neighbor {ip-address | peer-group-name} distribute-list access-list-number {in | out}
no neighbor {ip-address | peer-group-name} distribute-list access-list-number {in | out}Syntax Description
Default
No BGP neighbor is specified.
Command Mode
Router configuration
Usage Guidelines
Using distribute lists is one of two ways to filter BGP advertisements. The other way is to use AS-path filters, as with the ip as-path access-list global configuration command and the neighbor filter-list command.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.
Example
The following example applies list 39 to incoming advertisements to neighbor 120.23.4.1:
router bgp 109network 131.108.0.0neighbor 120.23.4.1 distribute-list 39 inRelated Commands
ip as-path access-list
neighbor filter-list
neighbor peer-group (creating)neighbor ebgp-multihop
To accept and attempt BGP connections to external peers residing on networks that are not directly connected, use the neighbor ebgp-multihop router configuration command. To return to the default, use the no form of this command.
neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]
no neighbor {ip-address | peer-group-name} ebgp-multihopSyntax Description
ip-address
IP address of the BGP-speaking neighbor.
peer-group-name
Name of a BGP peer group.
ttl
Time-to-live in the range 1 to 255 hops.
Default
Only directly connected neighbors are allowed.
Command Mode
Router configuration
Usage Guidelines
This feature should only be used under the guidance of technical support staff.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
Example
The following example allows connections to or from neighbor 131.108.1.1, which resides on a network that is not directly connected:
router bgp 109neighbor 131.108.1.1 ebgp-multihopRelated Command
neighbor peer-group (creating)
neighbor filter-list
To set up a BGP filter, use the neighbor filter-list router configuration command. To disable this function, use the no form of this command.
neighbor {ip-address | peer-group-name} filter-list access-list-number {in | out |
weight weight}
no neighbor {ip-address | peer-group-name} filter-list access-list-number {in | out |
weight weight}Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
This command establishes filters on both inbound and outbound BGP routes. Any number of weight filters are allowed on a per-neighbor basis, but only one in or out filter is allowed. The weight of a route affects BGP's route-selection rules.
The implemented weight is based on the first matched autonomous system path. Weights indicated when an autonomous system path is matched override the weights assigned by global neighbor commands. In other words, the weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.
See the "Regular Expressions" appendix for information on forming regular expressions.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.
Example
In the following example, the BGP neighbor with IP address 128.125.1.1 is not sent advertisements about any path through or from the adjacent autonomous system 123:
ip as-path access-list 1 deny _123_ip as-path access-list 1 deny ^123$router bgp 109network 131.108.0.0neighbor 129.140.6.6 remote-as 123neighbor 128.125.1.1 remote-as 47neighbor 128.125.1.1 filter-list 1 outRelated Commands
ip as-path access-list
neighbor distribute-list
neighbor peer-group (creating)
neighbor weightneighbor neighbor-list
To configure BGP to support anonymous neighbor peers by configuring a neighbor template, use the neighbor neighbor-list router configuration command. To delete a template, use the no form of this command.
neighbor template-name neighbor-list access-list-number
no neighbor template-name neighbor-listSyntax Description
template-name
User-selectable designation that identifies a particular template (an arbitrary word).
access-list-number
Number of an access list. It can be a number in the range 1 through 99.
Default
No configuration is defined.
Command Mode
Router configuration
Usage Guidelines
To specify a group of anonymous neighbors, configure a neighbor template rather than specifically configure each neighbor. The template allows you to specify an IP access list which defines remote systems that can establish a BGP connection to the router. External BGP peers must be on a directly connected Ethernet unless they are overridden by the neighbor ebgp-multihop command.
Once you specify a template, you configure the template as if it were a regular neighbor entry, such as setting the protocol version or filter lists, so that anonymous neighbors accepted by the template will receive the settings of the template.
These neighbors accepted by the template appear in the show ip bgp summary and show ip bgp neighbors displays, although they do not appear in the router configuration. When the session is disconnected, all knowledge about the neighbor is discarded and the router will not attempt to actively reestablish a connection.
You can use the neighbor configure-neighbors command to request that the router treat peers learned through a template as if they were manually configured neighbors. These peers will then show up in write terminal displays and can be stored as part of the nonvolatile configuration.
The no neighbor neighbor-list command deletes the template and cause any temporary neighbors accepted by the template to be shut down and removed.
Examples
In the following example, any BGP speaker from 168.89.3.0 can connect to the router and exchange information:
access-list 7 permit 168.89.3.0 0.0.0.255neighbor internal-ethernet neighbor-list 7
neighbor internal-ethernet configure-neighborsIn the following example, any BGP speaker in the connected internet can establish a BGP connection to the local router, and the local router will send them routing information. However, the distribute-list clause instructs the local router to ignore all information these remote BGP speakers send to it.
access-list 9 permit 0.0.0.0 255.255.255.255access-list 10 deny 0.0.0.0 255.255.255.255neighbor route-server-peers neighbor-list 9neighbor route-server-peers distribute-list 10 inRelated Commands
A dagger (†) indicates that the command is documented in another chapter.
access-list (standard) †
neighbor configure-neighbors
neighbor ebgp-multihopneighbor next-hop-self
To disable next-hop processing of BGP updates on the router, use the neighbor next-hop-self router configuration command. To disable this feature, use the no form of this command.
neighbor {ip-address | peer-group-name} next-hop-self
no neighbor {ip-address || peer-group-name} next-hop-selfSyntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
This command is useful in nonmeshed networks such as Frame Relay or X.25 where BGP neighbors may not have direct access to all other neighbors on the same IP subnet.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.
Example
The following example forces all updates destined for 131.108.1.1 to advertise this router as the next hop:
router bgp 109neighbor 131.108.1.1 next-hop-selfRelated Command
neighbor peer-group (creating)
neighbor password
To enable MD5 authentication on a TCP connection between two BGP peers, use the neighbor password router configuration command. To disable this feature, use the no form of this command.
neighbor {ip-address | peer-group-name} password string
no neighbor {ip-address | peer-group-name} passwordSyntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
You can invoke authentication between two BGP peers, causing each segment sent on the TCP connection between them to be verified. This feature must be configured with the same password on both BGP peers; otherwise, the connection between them will not be made. The authentication feature uses the MD5 algorithm. Specifying this command causes the generation and checking of the MD5 digest on every segment sent on the TCP connection.
Configuring a password for a neighbor will cause an existing session to be torn down and a new one established.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
If a router has a password configured for a neighbor, but the neighbor router does not, a message like the following will appear on the console while the routers attempt to establish a BGP session between them:
%TCP-6-BADAUTH: No MD5 digest from [peer's IP address]:11003 to [local router's IP address]:179Similarly, if the two routers have different passwords configured, a message like the following will appear on the console:
%TCP-6-BADAUTH: Invalid MD5 digest from [peer's IP address]:11004 to [local router's IP address]:179Example
The following example enables the authentication feature between this router and the BGP neighbor at 131.102.1.1. The password that must also be configured for the neighbor is bla4u00=2nkq.
router bgp 109neighbor 131.108.1.1 password bla4u00=2nkqRelated Command
neighbor peer-group (creating)
neighbor peer-group (creating)
To create a BGP peer group, use the neighbor peer-group router configuration command. To remove the peer group and all of its members, use the no form of this command.
neighbor peer-group-name peer-group
no neighbor peer-group-name peer-groupSyntax Description
Default
There is no BGP peer group.
Command Mode
Router configuration
Usage Guidelines
Often in a BGP speaker, there are many neighbors configured with the same update policies (that is, same outbound route maps, distribute lists, filter lists, update source, and so on). Neighbors with the same update policies can be grouped into peer groups to simplify configuration and make update calculation more efficient.
Once a peer group is created with the neighbor peer-group command, it can be configured with the neighbor commands. By default, members of the peer group inherit all of the configuration options of the peer group. Members can also be configured to override the options that do not affect outbound updates.
Peer group members will always inherit the following: remote-as (if configured), version, update-source, out-route-map, out-filter-list, out-dist-list, minimum-advertisement-interval, and next-hop-self. All of the peer group members will inherit changes made to the peer group.
If a peer group is not configured with a remote-as, the members can be configured with the neighbor {ip-address | peer-group-name} remote-as command. This allows you to create peer groups containing EBGP neighbors.
Example for an IBGP Peer Group
In the following example, the peer group named internal configures the members of the peer group to be IBGP neighbors. By definition, this is an IBGP peer group because the router bgp command and the neighbor remote-as command indicate the same autonomous system (in this case, AS 100). All the peer group members use loopback 0 as the update source and use set-med as the outbound route-map. The inbound filter-list command shows that except 171.69.232.55 all the neighbor has filter-list 2 as the inbound filter list.
router bgp 100neighbor internal peer-groupneighbor internal remote-as 100neighbor internal update-source loopback 0neighbor internal route-map set-med outneighbor internal filter-list 1 outneighbor internal filter-list 2 inneighbor 171.69.232.53 peer-group internalneighbor 171.69.232.54 peer-group internalneighbor 171.69.232.55 peer-group internalneighbor 171.69.232.55 filter-list 3 inExample for an EBGP Peer Group
In the following example, the peer group external-peers is defined without the neighbor remote-as command. This is what makes it an EBGP peer group. Each individaul member of the peer group is configured with its respective AS-number separately. Thus the peer group consists of members from autonomous systems 200, 300 and 400. All the peer group members have set-metric route map as an outbound route map and filter-list 99 as an outbound filter list. Except for neighbor 171.69.232.110, all of them have 101 as the inbound filter list.
router bgp 100neighbor external-peers peer-groupneighbor external-peers route-map set-metric outneigbhor external-peers filter-list 99 outneighbor external-peers filter-list 101 inneighbor 171.69.232.90 remote-as 200neighbor 171.69.232.90 peer-group external-peersneighbor 171.69.232.100 remote-as 300neighbor 171.69.232.100 peer-group external-peersneighbor 171.69.232.110 remote-as 400neighbor 171.69.232.110 peer-group external-peersneighbor 171.69.232.110 filter-list 400 inRelated Commands
clear ip bgp peer-group
neighbor remote-as
neighbor peer-group (assigning members)
show ip bgp peer-groupneighbor peer-group (assigning members)
To configure a BGP neighbor to be a member of a peer group, use the neighbor peer-group router configuration command. To remove the neighbor from the peer group, use the no form of this command.
neighbor ip-address peer-group peer-group-name
no neighbor ip-address peer-group peer-group-nameSyntax Description
ip-address
IP address of the BGP neighbor who belongs to the peer group specified by the tag.
peer-group-name
Name of the BGP peer group to which this neighbor belongs.
Default
There are no BGP neighbors in a peer group.
Command Mode
Router configuration
Usage Guidelines
The neighbor at the IP address indicated inherits all the configured options of the peer group.
Example
In the following example,
router bgp 100neighbor internal peer-groupneighbor internal remote-as 100neighbor internal update-source loopback 0neighbor internal route-map set-med outneighbor internal filter-list 1 outneighbor internal filter-list 2 inneighbor 171.69.232.53 peer-group internalneighbor 171.69.232.54 peer-group internalneighbor 171.69.232.55 peer-group internalneighbor 171.69.232.55 filter-list 3 inRelated Commands
neighbor peer-group (creating)
neighbor remote-asneighbor remote-as
To add an entry to the BGP neighbor table, use the neighbor remote-as router configuration command. To remove an entry from the table, use the no form of this command.
neighbor {ip-address | peer-group-name} remote-as number
no neighbor {ip-address | peer-group-name} remote-as numberSyntax Description
ip-address
Neighbor's IP address.
peer-group-name
Name of a BGP peer group.
number
Autonomous system to which the neighbor belongs.
Default
There are no BGP neighbor peers.
Command Mode
Router configuration
Usage Guidelines
Specifying a neighbor with an autonomous system number that matches the autonomous system number specified in the router bgp global configuration command identifies the neighbor as internal to the local autonomous system. Otherwise, the neighbor is considered external.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
Examples
The following example specifies that the router at the address 131.108.1.2 is a neighbor in autonomous system number 109:
router bgp 110network 131.108.0.0neighbor 131.108.1.2 remote-as 109In the following example, a BGP router is assigned to autonomous system 109, and two networks are listed as originating in the autonomous system. Then the addresses of three remote routers (and their autonomous systems) are listed. The router being configured will share information about networks 131.108.0.0 and 192.31.7.0 with the neighbor routers. The first router listed is in the same Class B network address space, but in a different autonomous system; the second neighbor command illustrates specification of an internal neighbor (with the same autonomous system number) at address 131.108.234.2; and the last neighbor command specifies a neighbor on a different network.
router bgp 109network 131.108.0.0network 192.31.7.0neighbor 131.108.200.1 remote-as 167neighbor 131.108.234.2 remote-as 109neighbor 150.136.64.19 remote-as 99Related Command
neighbor peer-group (creating)
neighbor route-map
To apply a route map to incoming or outgoing routes, use the neighbor route-map router configuration command. To remove a route map, use the no form of this command.
neighbor {ip-address | peer-group-name} route-map route-map-name {in | out}
no neighbor {ip-address | peer-group-name} route-map route-map-name {in | out}Syntax Description
ip-address
Neighbor's IP address.
peer-group-name
Name of a BGP peer group.
route-map-name
Name of route map.
in
Apply to incoming routes.
out
Apply to outgoing routes.
Default
No route maps are applied to a peer.
Command Mode
Router configuration
Usage Guidelines
If an outbound route map is specified, it is proper behavior to only advertise routes that match at least one section of the route map.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.
Example
In the following example, route map "internal-map" is applied to incoming route from 198.92.70.24:
router bgp 5neighbor 198.92.70.24 route-map internal-map in!route-map internal-mapmatch as-path 1set local-preference 100Related Command
neighbor peer-group (creating)
neighbor send-community
To specify that a COMMUNITIES attribute should be sent to a BGP neighbor, use the neighbor send-community router configuration command. To remove the entry, use the no form of this command.
neighbor {ip-address | peer-group-name} send-community
no neighbor {ip-address | peer-group-name} send-communitySyntax Description
Default
No COMMUNITIES attribute is sent to any neighbor.
Command Mode
Router configuration
Usage Guidelines
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
Example
In the following example, the router belongs to autonomous system 109 and is configured to send the COMMUNITIES attribute to its neighbor at IP address 198.92.70.23:
router bgp 109neighbor 198.92.70.23 send-communityRelated Commands
ip community-list
match community-list
neighbor peer-group (creating)
set communityneighbor third-party
To send updates regarding EGP third-party routers, use the neighbor third-party router configuration command. To disable these updates, use the no form of this command.
neighbor ip-address third-party third-party-ip-address [internal | external]
no neighbor ip-address third-party third-party-ip-address [internal | external]Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
Using this third-party mechanism, EGP tells its peer that another router (the third party) on the shared network is the appropriate router for some set of destinations. If updates mentioning third-party routers are desired, use this command.
All networks reachable through the third-party router will be listed in the EGP updates as reachable by the router. The optional internal and external keywords indicate whether the third-party router should be listed in the internal or external section of the EGP update. Normally, all networks are mentioned in the internal section.
This command can be used multiple times to specify additional third-party routers.
Examples
In the following example, routes learned from router 131.108.6.99 will be advertised to 131.108.6.5 as third-party internal routes:
neighbor 131.108.6.5 third-party 131.108.6.99 internalIn the following example, routes learned from 131.108.6.100 will be advertised to 131.108.6.5 as third-party external routes:
neighbor 131.108.6.5 third-party 131.108.6.100 externalneighbor update-source
To have the router allow internal BGP sessions to use any operational interface for TCP connections, use the neighbor update-source router configuration command. To restore the interface assignment to the closest interface, which is called the best local address, use the no form of this command
neighbor {ip-address | peer-group-name} update-source interface
no neighbor {ip-address | peer-group-name} update-source interfaceSyntax Description
ip-address
IP address of the BGP-speaking neighbor.
peer-group-name
Name of a BGP peer group.
interface
Loopback interface.
Default
Best local address
Command Mode
Router configuration
Usage Guidelines
This feature works in conjunction with the loopback interface feature described in the "Configuring Interfaces" chapter of the Router Products Configuration Guide.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
Example
In the following example, BGP TCP connections for the specified neighbor will be sourced with loopback interface's IP address rather than the best-local-address:
router bgp 110network 160.89.0.0neighbor 160.89.2.3 remote-as 110
neighbor 160.89.2.3 update-source Loopback0Related Command
neighbor peer-group (creating)
neighbor version
To configure the router to accept only a particular BGP version, use the neighbor version router configuration command. To use the default version level of a neighbor, use the no form of this command.
neighbor {ip-address | peer-group-name} version value
no neighbor {ip-address | peer-group-name} version valueSyntax Description
Default
BGP Version 4
Command Mode
Router configuration
Usage Guidelines
Entering this command disables dynamic version negotiation.
Our implementation of BGP supports BGP Versions 2, 3, and 4. If the neighbor does not accept default Version 4, dynamic version negotiation is implemented to negotiate down to Version 2.
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
Example
The following example locks down to Version 4 of the BGP protocol:
router bgp 109
neighbor 131.104.27.2 version 4Related Command
neighbor peer-group (creating)
neighbor weight
To assign a weight to a neighbor connection, use the neighbor weight router configuration command. To remove a weight assignment, use the no form of this command.
neighbor {ip-address | peer-group-name} weight weight
no neighbor {ip-address | peer-group-name} weight weightSyntax Description
ip-address
Neighbor's IP address.
peer-group-name
Name of a BGP peer group.
weight
Weight to assign. Acceptable values are 0 to 65535.
Default
Routes learned through another BGP peer have a default weight of 0 and routes sourced by the local router have a default weight of 32768.
Command Mode
Router configuration
Usage Guidelines
All routes learned from this neighbor will have the assigned weight initially. The route with the highest weight will be chosen as the preferred route when multiple routes are available to a particular network.
The weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.
Note
If you specify a BGP peer group by using the peer-group-name argument, all of the members of the peer group will inherit the characteristic configured with this command.
Example
The following example sets the weight of all routes learned via 151.23.12.1 to 50:
router bgp 109
neighbor 151.23.12.1 weight 50Related Commands
neighbor distribute-list
neighbor filter-list
neighbor peer-group (creating)net
To configure a Network Entity Title (NET) for the routing process, use the net router configuration command. To remove a NET, use the no form of this command.
net network-entity-title
no net network-entity-titleSyntax Description
network-entity-title
NET that specifies the area address and the system ID for an IS-IS routing process. This argument can be either an address or a name.
Default
No NET is configured.
Command Mode
Router configuration
Usage Guidelines
For IS-IS, multiple NETs per router are allowed, with a maximum of three. There is no default value for this command.
Example
The following example specifies a single NET:
router isis Pieintheskynet 47.0004.004d.0001.0000.0c11.1111.00network (BGP)
To specify the list of networks for the BGP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.
network network-number [mask network-mask]
no network network-number [mask network-mask]Syntax Description
Default
No networks are specified.
Command Mode
Router configuration
Usage Guidelines
These types of networks can be learned from connected routes, dynamic routing, and from static route sources.
A maximum of 200 network commands may be specified for a single BGP process.
Example
The following example sets up network 131.108.0.0 to be included in the router's BGP updates:
router bgp 120network 131.108.0.0Related Commands
network backdoor
network mask
network weight
router bgpnetwork (EGP)
To specify the list of networks for the EGP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.
network network-number
no network network-numberSyntax Description
Default
No networks are specified.
Command Mode
Router configuration
Usage Guidelines
The networks to be advertised to the EGP peers of an EGP routing process are advertised with a distance of zero. The restrictions on the network you specify are that it must appear in the routing table, and the network number must not contain any subnet information. The network can be connected, statically configured, or redistributed into EGP from other routing protocols. Multiple commands can be used to specify additional networks.
Example
The following example illustrates a typical configuration for an EGP router process. The router is in autonomous system 109 and is peering with routers in autonomous system 164. It will advertise the networks 131.108.0.0 and 192.31.7.0 to the router in autonomous system 164, 10.2.0.2. The information sent and received from peer routers can be filtered in various ways, including blocking information from certain routers and suppressing the advertisement of specific routes.
autonomous-system 109router egp 164network 131.108.0.0network 192.31.7.0neighbor 10.2.0.2Related Command
network (IGRP and Enhanced IGRP)
To specify a list of networks for the Enhanced IGRP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.
network network-number
no network network-numberSyntax Description
Default
No networks are specified.
Command Mode
Router configuration
Usage Guidelines
The network number specified must not contain any subnet information. You can specify multiple network commands.
IGRP or Enhanced IGRP sends updates to the interfaces in the specified network(s). Also, if an interface's network is not specified, it will not be advertised in any IGRP or Enhanced IGRP update.
Example
The following example configures a router for IGRP and assigns autonomous system 109. The network commands indicate the networks directly connected to the router.
router igrp 109network 131.108.0.0network 192.31.7.0Related Commands
network (RIP)
To specify a list of networks for the RIP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.
network network-number
no network network-numberSyntax Description
Default
No networks are specified.
Command Mode
Router configuration
Usage Guidelines
The network number specified must not contain any subnet information. You can specify multiple network commands. RIP routing updates will be sent and received only through interfaces on this network.
RIP sends updates to the interfaces in the specified network(s). Also, if an interface's network is not specified, it will not be advertised in any RIP update.
Example
The following example defines RIP as the routing protocol to be used on all interfaces connected to networks 128.99.0.0 and 192.31.7.0:
router ripnetwork 128.99.0.0network 192.31.7.0Related Command
network area
To define the interfaces on which OSPF runs and to define the area ID for those interfaces, use the network area router configuration command. To disable OSPF routing for interfaces defined with the address wildcard-mask pair, use the no form of this command.
network address wildcard-mask area area-id
no network address wildcard-mask area area-idSyntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
The address and wildcard-mask arguments together allow you to define one or multiple interfaces to be associated with a specific OSPF area using a single command. Using the wildcard-mask allows you to define one or multiple interfaces to be associated with a specific OSPF area using a single command. If you intend to associate areas with IP subnets, you can specify a subnet address as the area-id.
For OSPF to operate on the interface, that interface's primary address must be covered by the network area command. If the network area command covers only the secondary address, it will not enable OSPF over that interface.
The router sequentially evaluates the address/wildcard-mask pair for each interface as follows:
1
2
3
4
Note
Example
In the following partial example, OSPF routing process 109 is initialized, and four OSPF areas are defined: 10.9.50.0, 2, 3, and 0. Areas 10.9.50.0, 2, and 3 mask specific address ranges, while area 0 enables OSPF for all other networks.
interface ethernet 0ip address 131.108.20.1 255.255.255.0router ospf 109network 131.108.20.0 0.0.0.255 area 10.9.50.0network 131.108.0.0 0.0.255.255 area 2network 131.109.10.0 0.0.0.255 area 3network 0.0.0.0 255.255.255.255 area 0Related Command
network backdoor
To specify a backdoor route to a BGP border router that will provide better information about the network, use the network backdoor router configuration command. To remove an address from the list, use the no form of this command.
network address backdoor
no network address backdoorSyntax Description
Default
No network is advertised.
Command Mode
Router configuration
Usage Guidelines
A backdoor network is treated as a local network, except that it is not advertised.
Example
The following example configures network 131.108.0.0 as a local network and network 192.31.7.0 as a backdoor network:
router bgp 109network 131.108.0.0network 192.31.7.0 backdoornetwork weight
To assign an absolute weight to a BGP network, use the network weight router configuration command. To delete an entry, use the no form of the command.
network address weight weight
no network address weight weightSyntax Description
address
IP address of the network.
weight
Absolute weight, or importance. It can be an integer from 0 to 65535.
Default
Weight is unmodified. Weight is zero if the original default weight has not been modified by other router configuration commands.
Command Mode
Router configuration
Usage Guidelines
The weight specified by this command overrides a weight assigned by the redistribute command.
Example
In the following example, the BGP network has a weight of 100:
router bgp 5network 193.0.0.0 weight 100offset-list
To add an offset to incoming and outgoing metrics to routes learned via RIP and IGRP, use the offset-list router configuration command. To remove an offset list, use the no form of this command.
offset-list [access-list-number] {in | out} offset [type number]
no offset-list [access-list-number] {in | out} offset [type number]Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
The offset value is added to the routing metric. An offset-list with an interface type and interface number is considered extended and takes precedence over an offset-list that is not extended. Therefore, if an entry passes the extended offset-list and the normal offset-list, the extended offset-list's offset is added to the metric.
Examples
In the following example, the router applies an offset of 10 to the router's delay component to access list 21:
offset-list 21 out 10In the following example of an extended offset-list, the router applies the offset of 10 to routes learned from Ethernet interface 0:
offset-list in 10 ethernet 0ospf auto-cost-determination
To control how OSPF calculates default metrics for the interface, use the ospf auto-cost-determination router configuration command. To disable this feature, use the no form of this command.
ospf auto-cost-determination
no ospf auto-cost-determinationSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Router configuration
Usage Guidelines
In Cisco IOS Release 10.2 and earlier, OSPF assigns default OSPF metrics to interfaces regardless of the interface bandwidth. It gives both 64K and T1 links the same metric (1562), and thus requires an explicit ip ospf cost command in order to take advantage of the faster link.
In Cisco IOS Release 10.3 and later, by default OSPF will calculate the OSPF metric for an interface according to the bandwidth of the interface. For example, a 64K link will get a metric of 1562, while a T1 link will have a metric of 64.
The OSPF metric is calculated as metric-scale / bandwidth, with metric-scale equal to 108 by default, giving FDDI a metric of 1.
Example
The following example causes a fixed default metric assignment, regardless of interface bandwidth:
router ospf 1no ospf auto-cost-determinationRelated Command
ip ospf cost
passive-interface
To disable sending routing updates on an interface, use the passive-interface router configuration command. To reenable the sending of routing updates, use the no form of this command.
passive-interface type number
no passive-interface type numberSyntax Description
Default
Routing updates are sent on the interface.
Command Mode
Router configuration
Usage Guidelines
If you disable the sending of routing updates on an interface, the particular subnet will continue to be advertised to other interfaces, and updates from other routers on that interface continue to be received and processed.
For OSPF, OSPF routing information is neither sent nor received through the specified router interface. The specified interface address appears as a stub network in the OSPF domain.
For IS-IS, this command instructs IS-IS to advertise the IP addresses for the specified interface without actually running IS-IS on that interface. The no form of this command for IS-IS disables advertising IP addresses for the specified address.
Enhanced IGRP is disabled on an interface that is configured as passive although it advertises the route.
Examples
The following example sends IGRP updates to all interfaces on network 131.108.0.0 except Ethernet interface 1:
router igrp 109network 131.108.0.0passive-interface ethernet 1The following configuration enables IS-IS on interfaces Ethernet 1 and serial 0 and advertises the IP addresses of Ethernet 0 in its Link State PDUs:
router isis Financepassive-interface Ethernet 0interface Ethernet 1ip router isis Financeinterface serial 0ip router isis Financeping
To send an ICMP Echo Request to a multicast group, use the ping EXEC command.
ping [group-anme-or-address]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.2.
If you use this command with no argument, the system prompts you.
mrinfo
To query what neighboring multicast routers are peering with the local router, use the mrinfo EXEC command.
mrinfo [hostname-or-address] [source-address-or-interface]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
The mrinfo command is the MBONE's original tool to determine what neighboring multicast routers are peering with a multicast router. Cisco routers have supported responding to mrinfo requests since Cisco IOS Release 10.2.
Now you can query a multicast router using this command. The output format is identical to DVMRP's mrouted version. (The mrouted software is the UNIX software that implements DVMRP.)
Sample Display
The following is sample output of the mrinfo command:
Router # mrinfo192.31.7.37 (barrnet-gw.cisco.com) [version cisco 11.1] [flags: PMSA]:192.31.7.37 -> 192.31.7.34 (sj-wall-2.cisco.com) [1/0/pim]192.31.7.37 -> 192.31.7.47 (dirtylab-gw-2.cisco.com) [1/0/pim]192.31.7.37 -> 192.31.7.44 (dirtylab-gw-1.cisco.com) [1/0/pim]131.119.26.10 -> 131.119.26.9 (su-pr2.bbnplanet.net) [1/32/pim]mstat
To display IP multicast packet rate and loss information, use the mstat user EXEC command.
mstat source [destination] [group]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
If no arguments are entered, the router will interactively prompt you for them.
This command is a form of UNIX mtrace that reports packet rate and loss information.
Sample Display
The following is sample output from the mstat command:
Router# mstat dino-ss2 dino-ss20 224.0.255.255Type escape sequence to abort.Mtrace from 171.69.129.220 to 171.69.58.81 via group 224.0.255.255>From source (dino-ss2.cisco.com) to destination (dino-ss20.cisco.com)Waiting to accumulate statistics......Results after 10 seconds:Source Response Dest Packet Statistics For Only For Traffic171.69.129.220 171.69.129.217 All Multicast Traffic From 171.69.129.220| __/ rtt 211 ms Lost/Sent = Pct Rate To 224.0.255.255v / hop 131 ms --------------------- --------------------171.69.129.217 DINO-CISCO-FR| ^ ttl 0v | hop -6 ms 12/13 = 92% 1 pps 0/2 = --% 0 pps171.69.121.35 eng-fr-2.cisco.com| ^ ttl 1v | hop 3 ms 0/13 = --% 0 pps 0/2 = --% 0 pps171.69.121.2171.69.5.26 sj-eng-cc4.cisco.com| ^ ttl 2v | hop 0 ms 0/23 = --% 0 pps -2/2 = --% 0 pps171.69.5.21171.69.62.130 eng-ios-2.cisco.com| ^ ttl 3v | hop 1 ms 0/903 = --% 0 pps -18471/4 = --% 0 ppsRelated Command
mtrace
To trace the path from a source to a destination branch for a multicast distribution tree, use the mtrace user EXEC command.
mtrace source [destination] [group]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
The trace request generated by the mtrace command is multicast to the multicast group to find the last hop router to the specified destination. The trace then follows the multicast path from destination to source by passing the mtrace request packet via unicast to each hop. Responses are unicast to the querying router by the first hop router to the source. This command allows you to isolate multicast routing failures.
If no arguments are entered, the router will interactively prompt you for them.
This command is identical in function to the UNIX version of mtrace.
Sample Display
The following is sample output from the mtrace command:
Router> mtrace 171.69.215.41 171.69.215.67 239.254.254.254Type escape sequence to abort.Mtrace from 171.69.215.41 to 171.69.215.67 via group 239.254.254.254From source (?) to destination (?)Querying full reverse path...0 171.69.215.67-1 171.69.215.67 PIM thresh^ 0 0 ms-2 171.69.215.74 PIM thresh^ 0 2 ms-3 171.69.215.57 PIM thresh^ 0 894 ms-4 171.69.215.41 PIM thresh^ 0 893 ms-5 171.69.215.12 PIM thresh^ 0 894 ms-6 171.69.215.98 PIM thresh^ 0 893 msdescribes the fields shown in the display.
Table 19-6 Mtrace Field Descriptions
Related Command
mstat
output-delay
To change the interpacket delay for RIP updates sent, use the output-delay router configuration command. To remove the delay, use the no form of this command.
output-delay delay
no output-delay [delay]Syntax Description
delay
Delay, in milliseconds, between packets in a multiple-packet RIP update. The range is 8 to 50 milliseconds. The default is no delay.
Default
0 milliseconds
Command Mode
Router configuration
Usage Guidelines
Consider using this command if you have a high-end router sending at high speed to a low-speed router that might not be able to receive at that fast a rate. Configuring this command will help prevent the routing table from losing information.
Example
In the following example, the interpacket delay is set to 10 milliseconds:
output-delay 10redistribute
To redistribute routes from one routing domain into another routing domain, use the redistribute router configuration command. To disable redistribution, use the no form of this command.
redistribute protocol [process-id] {level-1 | level-1-2 | level-2} [metric metric-value]
[metric-type type-value] [match {internal | external 1 | external 2}]
[tag tag-value] [route-map map-tag] [weight weight] [subnets]
no redistribute protocol [process-id] {level-1 | level-1-2 | level-2} [metric metric-value]
[metric-type type-value] [match {internal | external 1 | external 2}]
[tag tag-value] [route-map map-tag] [weight weight] [subnets]Syntax Description
Default
Route redistribution is disabled.
Command Mode
Router configuration
Usage Guidelines
Changing or disabling any keyword will not affect the state of other keywords.
A router receiving a link-state protocol (LSP) with an internal metric will consider the cost of the route from itself to the redistributing router plus the advertised cost to reach the destination. An external metric only considers the advertised metric to reach the destination.
Routes learned from IP routing protocols can be redistributed at level-1 into an attached area or at level-2. The keyword level-1-2 allows both in a single command.
Redistributed routing information should always be filtered by the distribute-list out router configuration command. This ensures that only those routes intended by the administrator are passed along to the receiving routing protocol.
Whenever you use the redistribute or the default-information router configuration commands to redistribute routes into an OSPF routing domain, the router automatically becomes an Autonomous System Boundary Router (ASBR). However, an ASBR does not, by default, generate a default route into the OSPF routing domain.
When routes are redistributed between OSPF processes, no OSPF metrics are preserved.
When routes are redistributed into OSPF and no metric is specified in the metric keyword, the default metric that OSPF uses is 20 for routes from all protocols except BGP route, which gets a metric of 1.
When redistributing routes into OSPF, only routes that are not subnetted are redistributed if the subnets keyword is not specified.
The only connected routes affected by this redistribute command are the routes not specified by the network command.
You cannot use the default-metric command to affect the metric used to advertise connected routes.
Note
Default redistribution of IGPs or EGP into BGP is not allowed unless default-information originate is specified.
Examples
The following are examples of the various configurations you would use to redistribute one routing protocol into another routing protocol.
The following example configuration causes OSPF routes to be redistributed into a BGP domain:
router bgp 109redistribute ospf...The following example configuration causes IGRP routes to be redistributed into an OSPF domain:
router ospf 110redistribute igrp...The following example causes the specified IGRP process routes to be redistributed into an OSPF domain. The IGRP-derived metric will be remapped to 100 and RIP routes to 200.
router ospf 109redistribute igrp 108 metric 100 subnetsredistribute rip metric 200 subnetsIn the following example, BGP routes are configured to be redistributed into IS-IS. The link-state cost is specified as 5, and the metric type will be set to external, indicating that it has lower priority than internal metrics.
router isisredistribute bgp 120 metric 5 metric-type externalRelated Commands
default-information originate (BGP)
default-information originate (EGP)
default-information originate (IS-IS)
default-information originate (OSPF)
distribute-list out
route-map
show route-maproute-map
To define the conditions for redistributing routes from one routing protocol into another, or to enable policy routing, use the route-map global configuration command and the match and set route-map configuration commands. To delete an entry, use the no route-map command.
route-map map-tag [permit | deny] [sequence-number]
no route-map map-tag [permit | deny] [sequence-number]Syntax Description
Default
No default is available.
Command Mode
Global configuration
Usage Guidelines
Use route maps to redistribute routes or to subject packets to policy routing. Both purposes are described in this section.
•
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The related match commands are listed in the section " Related Commands for Redistribution." The match commands can be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
Use route maps when you want detailed control over how routes are redistributed between routing processes. The destination routing protocol is the one you specify with the router global configuration command. The source routing protocol is the one you specify with the redistribute router configuration command. See the following example as an illustration of how route maps are configured.
When you are passing routes through a route map, a route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
•
Another purpose of route maps is to enable policy routing. Use the ip policy route-map command, in addition to the route-map command, and the match and set commands to define the conditions for policy routing packets. The related match and set commands are listed in the section " Related Commands for Policy Routing." The match commands specify the conditions under which policy routing occurs. The set commands specify the routing actions to perform if the criteria enforced by the match commands are met. You might want to policy route packets some way other than the obvious shortest path.
The sequence-number works as follows:
1
2
3
If no route-map map-tag is specified (with no sequence-number), the whole route-map is deleted.
Examples
The following example redistributes all OSPF routes into IGRP:
router igrp 109redistribute ospf 110default metric 1000 100 255 1 1500The following example redistributes RIP routes with a hop count equal to 1 into OSPF. These routes will be redistributed into OSPF as external link state advertisements with a metric of 5, metric type of Type 1 and a tag equal to 1.
router ospf 109redistribute rip route-map rip-to-ospfroute-map rip-to-ospf permitmatch metric 1set metric 5set metric-type type1set tag 1Related Commands for Redistribution
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight
show ip policy
show route-mapRelated Commands for Policy Routing
ip policy route-map
match ip address
match length
set default interface
set interface
set ip default next-hop
set ip next-hop
show ip policyrouter bgp
To configure the Border Gateway Protocol (BGP) routing process, use the router bgp global configuration command. To remove a routing process, use the no form of this command.
router bgp autonomous-system
no router bgp autonomous-systemSyntax Description
autonomous-system
Number of an autonomous system that identifies the router to other BGP routers and tags the routing information passed along.
Default
No BGP routing process is enabled by default.
Command Mode
Global configuration
Usage Guidelines
This command allows you to set up a distributed routing core that automatically guarantees the loop-free exchange of routing information between autonomous systems.
Example
The following example configures a BGP process for autonomous system 120:
router bgp 120Related Commands
neighbor
network (BGP)
timers bgprouter egp
To configure the Exterior Gateway Protocol (EGP) routing process, use the router egp global configuration command. To turn off an EGP routing process, use the no router egp command.
router egp remote-as
no router egp remote-asSyntax Description
remote-as
Autonomous system number the router expects its peers to be advertising in their EGP messages.
Default
No EGP routing process is defined.
Command Mode
Global configuration
Usage Guidelines
You must specify the autonomous system number before starting EGP. The local autonomous system number will be included in EGP messages sent by the router. The software does not insist that the actual remote autonomous system number match the configured autonomous system numbers. The output from the debug ip-egp EXEC command will advise of any discrepancies.
Example
The following example assigns a router to autonomous system 109 and is peering with routers in autonomous system 164:
autonomous-system 109
router egp 164Related Commands
autonomous-system (EGP)
neighbor
network (EGP)
timers egprouter egp 0
To specify that a router should be considered a core gateway, use the router egp 0 global configuration command. To disable this function, use the no form of this command.
router egp 0
no router egp 0Syntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
Core gateways are central clearinghouses of routing information. Only one core gateway process can be configured in a router.
The router egp 0 global configuration command allows a specific router to have an EGP process that will enable it to act as a peer with any reachable autonomous system and information is exchanged freely between autonomous systems.
Normally, an EGP process expects to communicate with neighbors from a single autonomous system. Because all neighbors are in the same autonomous system, the EGP process assumes that these neighbors all have consistent internal information. Therefore, if the EGP process is informed about a route from one of its neighbors, it will not send it out to other neighbors.
With core EGP, the assumption is that all neighbors are from different autonomous systems, and all have inconsistent information. In this case, the EGP process distributes routes from one neighbor to all others (but not back to the originator). This allows the EGP process to be a central clearinghouse for information.
To control how an EGP process determines which neighbors will be treated as peers, use the neighbor any router configuration command with the router egp 0 global configuration command.
Example
The following example illustrates how an EGP core gateway can be configured:
access-list 1 permit 10.0.0.0 0.255.255.255! global access list assignmentrouter egp 0neighbor any 1network 131.108.0.0Related Commands
neighbor any
neighbor any third-partyrouter eigrp
To configure the Enhanced IGRP routing process, use the router eigrp global configuration command. To shut down a routing process, use the no form of this command.
router eigrp autonomous-system
no router eigrp autonomous-systemSyntax Description
autonomous-system
Autonomous system number that identifies the routes to the other Enhanced IGRP routers. It is also used to tag the routing information.
Default
Disabled
Command Mode
Global configuration
Example
The following example shows how to configure an Enhanced IGRP routing process and assign process number 109:
router eigrp 109Related Command
network (IGRP and Enhanced IGRP)
router igrp
To configure the Interior Gateway Routing Protocol (IGRP) routing process, use the router igrp global configuration command. To shut down an IGRP routing process, use the no form of this command.
router igrp autonomous-system
no router igrp autonomous-systemSyntax Description
autonomous-system
Autonomous system number that identifies the routes to the other IGRP routers. It is also used to tag the routing information.
Default
No IGRP routing process is defined.
Command Mode
Global configuration
Usage Guidelines
It is not necessary to have a registered autonomous system number to use IGRP. If you do not have a registered number, you are free to create your own. We recommend that if you do have a registered number, you use it to identify the IGRP process.
Example
The following example shows how to configure an IGRP routing process and assign process number 109:
router igrp 109Related Command
network (IGRP and Enhanced IGRP)
router isis
To enable the IS-IS routing protocol and to specify an IS-IS process for IP, use the router isis global configuration command. To disable IS-IS routing, use the no form of this command.
router isis [tag]
no router isis [tag]Syntax Description
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
You can specify only one IS-IS process per router. Only one IS-IS process is allowed whether you run it in integrated mode, ISO CLNS only, or IP only.
Example
The following example configures the router for IP routing and enables the IS-IS routing protocol:
ip routingrouter isisRelated Commands
router ospf
To configure an OSPF routing process, use the router ospf global configuration command. To terminate an OSPF routing process, use the no form of this command.
router ospf process-id
no router ospf process-idSyntax Description
process-id
Internally used identification parameter for an OSPF routing process. It is locally assigned and can be any positive integer. A unique value is assigned for each OSPF routing process.
Default
No OSPF routing process is defined.
Command Mode
Global configuration
Usage Guidelines
You can specify multiple OSPF routing processes in each router.
Example
The following example shows how to configure an OSPF routing process and assign a process number of 109:
router ospf 109Related Command
router rip
To configure the Routing Information Protocol (RIP) routing process, use the router rip global configuration command. To turn off the RIP routing process, use the no form of this command.
router rip
no router ripSyntax Description
This command has no arguments or keywords.
Default
No RIP routing process is defined.
Command Mode
Global configuration
Example
The following example shows how to begin the RIP routing process:
router ripRelated Command
set as-path
To modify an autonomous system path for BGP routes, use the set as-path route map configuration command. To not modify the autonomous system path, use the no form of this command.
set as-path {tag | prepend as-path-string}
no set as-path {tag | prepend as-path-string}Syntax Description
Default
Autonomous system path is not modified.
Command Mode
Route map configuration
Usage Guidelines
The only global BGP metric available to influence the best path selection is the AS-PATH length. By varying the length of the AS-PATH, a BGP speaker can influence the best path selection by a peer further away.
By allowing you to convert the tag into an autonomous system path, the set as-path tag variation of this command modifies the autonomous system length. The set as-path prepend variation allows you to prepend an arbitrary autonomous system path string to BGP routes. Usually the local autonomous system number is prepended multiple times. This increases the autonomous system path length.
Examples
The following example converts the tag of a redistributed route into an autonomous system path:
route-map set-as-path-from-tagmatch as-path 2set as-path prepend 100 100 100!router bgp 100redistribute ospf 109 route-map se t-as-path-from-tagThe following example prepends 100 100 100 to all the routes advertised to 131.108.1.1:
route-map set-as-pathmatch as-path 1set as-path prepend 100 100 100!router bgp 100neighbor 131.108.1.1 route-map set-as-path outRelated Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightset automatic-tag
To automatically compute the tag value, use the set automatic-tag route-map configuration command. To disable this function, use the no form of this command.
set automatic-tag
no set automatic-tagSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, the router is configured to automatically compute the tag value for the BGP learned routes:
route-map tagmatch as path 10set automatic-tag!router bgp 100table-map tagRelated Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightset community
To set the BGP COMMUNITIES attribute, use the set community route-map configuration command. To delete the entry, use the no form of this command.
set community {community-number [additive]} | none
no set community {community-number [additive]} | noneSyntax Description
Default
No BGP COMMUNITIES attributes exist.
Command Mode
Route-map configuration
Usage Guidelines
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, routes that pass the autonomous system path access list 1 have the community set to 109. Routes that pass the autonomous system path access list 2 have the community set to no-export (these routes will not be advertised to any EBGP peers).
route-map set_community 10 permitmatch as-path 1set community 109route-map set_community 20 permitmatch as-path 2set community no-exportRelated Commands
ip community-list
match community-list
route-mapset default interface
To indicate where to output packets that pass a match clause of a route map for policy routing and have no explicit route to the destination, use the set default interface route-map configuration command. To delete an entry, use the no form of this command.
set default interface type number [... type number]
no set default interface type number [... type number]Syntax Description
type
Interface type, used with the interface number, to which packets are output.
number
Interface number, used with the interface type, to which packets are output.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
Use this command to provide certain users a different default route. If the router has no explicit route for the destination, then it routes the packet to this interface. The first interface specified with the set default interface command that is up is used. The optionally specified interfaces are tried in turn.
Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which policy routing occurs. The set commands specify the set actions—the particular routing actions to perform if the criteria enforced by the match commands are met.
The set clauses can be used in conjunction with one another. They are evaluated in the following order:
set ip next-hop
set interface
set ip default next-hop
set default interfaceExample
In the following example, packets that have a Level 3 length of 3 to 50 bytes and for which the router has no explicit route to the destination are output to Ethernet interface 0:
interface serial 0ip policy route-map brighton!route-map brightonmatch length 3 50set default interface ethernet 0Related Commands
ip policy route-map
match ip address
match length
route-map
set interface
set ip default next-hop
set ip next-hopset interface
To indicate where to output packets that pass a match clause of route map for policy routing, use the set interface route-map configuration command. To delete an entry, use the no form of this command.
set interface type number [... type number]
no set interface type number [... type number]Syntax Description
type
Interface type, used with the interface number, to which packets are output.
number
Interface number, used with the interface type, to which packets are output.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which policy routing occurs. The set commands specify the set actions—the particular routing actions to perform if the criteria enforced by the match commands are met.
If the first interface specified with the set interface command is down, the optionally specified interfaces are tried in turn.
The set clauses can be used in conjunction with one another. They are evaluated in the following order:
set ip next-hop
set interface
set ip default next-hop
set default interfaceA useful next hop implies an interface. As soon as a next hop and an interface are found, the packet is routed.
Specifying set interface null 0 is a way to write a policy that the packet be dropped and an "unreachable" message be generated.
Example
In the following example, packets with a Level 3 length of 3 through 50 bytes are output to Ethernet interface 0:
interface serial 0ip policy route-map testing!route-map testingmatch length 3 50set interface ethernet 0Related Commands
ip policy route-map
match ip address
match length
route-map
set default interface
set ip default next-hop
set ip next-hopset ip default next-hop
To indicate where to output packets that pass a match clause of a route map for policy routing and for which the router has no explicit route to a destination, use the set ip default next-hop route-map configuration command. To delete an entry, use the no form of this command.
set ip default next-hop ip-address [... ip-address]
no set ip default next-hop ip-address [... ip-address]Syntax Description
ip-address
IP address of the next hop to which packets are output. It need not be an adjacent router.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
Use this command to provide certain users a different default route. If the router has no explicit route for the destination in the packet, then it routes the packet to this next hop. The first next hop specified with the set ip default next-hop command that appears to be adjacent to the router is used. The optional specified IP addresses are tried in turn.
Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which policy routing occurs. The set commands specify the set actions—the particular routing actions to perform if the criteria enforced by the match commands are met.
The set clauses can be used in conjunction with one another. They are evaluated in the following order:
set ip next-hop
set interface
set ip default next-hop
set default interfaceExample
The following example provides two sources with equal access to two different service providers. Packets arriving on async interface 1 from the source 1.1.1.1 are sent to the router at 6.6.6.6 if the router has no explicit route for the packet's destination. Packets arriving from the source 2.2.2.2 are sent to the router at 7.7.7.7 if the router has no explicit route for the packet's destination. All other packets for which the router has no explicit route to the destination are discarded.
access-list 1 permit ip 1.1.1.1 0.0.0.0access-list 2 permit ip 2.2.2.2 0.0.0.0!interface async 1ip policy route-map equal-access!route-map equal-access permit 10match ip address 1set ip default next-hop 6.6.6.6route-map equal-access permit 20match ip address 2set ip default next-hop 7.7.7.7route-map equal-access permit 30set default interface null0Related Commands
ip policy route-map
match ip address
match length
route-map
set default interface
set interface
set ip next-hopset ip next-hop
To indicate where to output packets that pass a match clause of a route map for policy routing, use the set ip next-hop route-map configuration command. To delete an entry, use the no form of this command.
set ip next-hop ip-address [... ip-address]
no set ip next-hop ip-address [... ip-address]Syntax Description
ip-address
IP address of the next hop to which packets are output. It need not be an adjacent router.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which policy routing occurs. The set commands specify the set actions—the particular routing actions to perform if the criteria enforced by the match commands are met.
If the first next hop specified with the set ip next-hop command is down, the optionally specified IP addresses are tried in turn.
The set clauses can be used in conjunction with one another. They are evaluated in the following order:
set ip next-hop
set interface
set ip default next-hop
set default interfaceExample
In the following example, packets with a Level 3 length of 3 to 50 bytes are output to the router at IP address 161.14.2.2:
interface serial 0ip policy route-map thataway!route-map thatawaymatch length 3 50set ip next-hop 161.14.2.2Related Commands
ip policy route-map
match ip address
match length
route-map
set default interface
set interface
set ip default next-hopset level
To indicate where to import routes, use the set level route-map configuration command. To delete an entry, use the no form of this command.
set level {level-1 | level-2 | level-1-2 | stub-area | backbone}
no set level {level-1 | level-2 | level-1-2 | stub-area | backbone}Syntax Description
Default
Disabled
For IS-IS destinations, the default value is level-2. For OSPF destinations, the default value is backbone.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, routes will be imported into the Level 1 area:
route-map nameset level level-lRelated Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weightset local-preference
To specify a preference value for the autonomous system path, use the set local-preference route-map configuration command. To delete an entry, use the no form of this command.
set local-preference value
no set local-preference valueSyntax Description
Default
Preference value of 100
Command Mode
Route-map configuration
Usage Guidelines
The preference is sent only to all routers in the local autonomous system.
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria— the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
You can change the default preference value with the bgp default local-preference command.
Example
In the following example, the local preference is set to 100 for all routes that are included in access list 1:
route-map map-preferencematch as-path 1set local-preference 100Related Commands
bgp default local-preference
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set metric
set metric-type
set next-hop
set origin
set tag
set weightset metric
To set the metric value for a routing protocol other than IGRP or IP Enhanced IGRP, use the set metric route-map configuration command. To return to the default metric value, use the no form of this command.
set metric metric-value
no set metric metric-valueSyntax Description
metric-value
Metric value or IGRP bandwidth in kilobits per second. It can be an integer from -294967295 through 294967295.
Default
Default metric value.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, the metric value for the destination routing protocol is set to 100:
route-map set-metricset metric 100Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric-type
set next-hop
set origin
set tag
set weightset metric
To set the metric value for IGRP or IP Enhanced IGRP in a route-map, use the set metric route-map configuration command. To return to the default metric value, use the no form of this command.
set metric bandwidth delay reliability loading mtu
no set metric bandwidth delay reliability loading mtuSyntax Description
Default
No metric will be set in the route-map.
Command Mode
Route-map configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Note
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, the bandwidth is set to 10,000, the delay is set to 10, the reliability is set to 255, the loading is set to 1, and the MTU is set to 1500:
set metric 10000 10 255 1 1500set metric-type
To set the metric type for the destination routing protocol, use the set metric-type route-map command. To return to the default, use the no form of this command.
set metric-type {internal | external | type-1 | type-2}
no set metric-type {internal | external | type-1 | type-2}Syntax Description
internal
IS-IS internal metric.
external
IS-IS external metric.
type-1
OSPF external type 1 metric.
type-2
OSPF external type 2 metric.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, the metric type of the destination protocol is set to OSPF external type 1:
route-map map-typeset metric-type type-1Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set next-hop
set origin
set tag
set weightset metric-type internal
To set the MED value on prefixes advertised to EBGP neighbors to match the IGP metric of the next hop, use the set metric internal route-map configuration command. To return to the default, use the no form of this command.
set metric-type internal
no set metric-type internalSyntax Description
This command has not arguments or keywords.
Default
Disabled
Command Mode
Route-map configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
This command will cause BGP to advertise a MED that corresponds to the IGP metric associated with the NEXT HOP of the route. This command applies to generated, iBGP-, and eBGP-derived routes.
If this command is used, multiple BGP speakers in a common AS can advertise different MEDs for a particular prefix. Also, note that if the IGP metric changes, BGP will not readvertise the route.
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, the MED for all the advertised routes to neighbor 160.89.2.3 is set to the corresponding IGP metric of the nexthop:
router bgp 109network 160.89.0.0neighbor 160.89.2.3 remote-as 200neighbor 160.89.2.3 route-map setMED out!route-map setMED permit 10match as-path 1set metric-type internal!ip as-path access-list 1 permit .*Related Commands
You can use the master indexes or search online to find documentation of related commands.
route-map
set next-hop
To specify the address of the next hop, use the set next-hop route-map configuration command. To delete an entry, use the no form of this command.
set next-hop next-hop
no set next-hop next-hopSyntax Description
Default
Default next-hop address.
Command Mode
Route-map configuration
Usage Guidelines
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria— the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, routes that pass the access list have the next hop set to 198.92.70.24:
route-map map_hopmatch address 5set next-hop 198.92.70.24Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set origin
set tag
set weightset origin
To set the BGP origin code, use the set origin route-map configuration command. To delete an entry, use the no form of this command.
set origin {igp | egp autonomous-system | incomplete}
Syntax Description
igp
Remote IGP.
egp
Local EGP.
autonomous-system
Remote autonomous system. This is an integer from 0 through 65535.
incomplete
Unknown heritage.
Default
Default origin, based on route in main IP routing table.
Command Mode
Route-map configuration
Usage Guidelines
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, routes that pass the route map have the origin set to IGP:
route-map set_originmatch as-path 10set origin igpRelated Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set tag
set weightset tag
To set a tag value of the destination routing protocol, use the set tag route-map configuration command. To delete the entry, use the no form of this command.
set tag tag-value
no set tag tag-valueSyntax Description
Default
If not specified, the default action is to forward the tag in the source routing protocol onto the new destination protocol.
Command Mode
Route-map configuration
Usage Guidelines
Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Example
In the following example, the tag value of the destination routing protocol is set to 5:
route-map tagset tag 5Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set weightset weight
To specify the BGP weight for the routing table, use the set weight route-map configuration command. To delete an entry, use the no form of this command.
set weight weight
no set weight weightSyntax Description
Default
The weight is not changed by the specified route map.
Command Mode
Route-map configuration
Usage Guidelines
You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.
The implemented weight is based on the first matched autonomous system path. Weights indicated when an autonomous system path is matched override the weights assigned by global neighbor commands. In other words, the weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.
Example
In the following example, the BGP weight for the routes matching the autonomous system path access list is set to 200:
route-map set-weightmatch as-path 10set weight 200Related Commands
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tagshow ip bgp
To display entries in the BGP routing table, use the show ip bgp EXEC command.
show ip bgp [network] [network-mask] [longer-prefixes]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output from the show ip bgp command:
Router# show ip bgpBGP table version is 716977, local router ID is 193.0.32.1Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path* i3.0.0.0 193.0.22.1 0 100 0 1800 1239 ?*>i 193.0.16.1 0 100 0 1800 1239 ?* i6.0.0.0 193.0.22.1 0 100 0 1800 690 568 ?*>i 193.0.16.1 0 100 0 1800 690 568 ?* i7.0.0.0 193.0.22.1 0 100 0 1800 701 35 ?*>i 193.0.16.1 0 100 0 1800 701 35 ?* 198.92.72.24 0 1878 704 701 35 ?* i8.0.0.0 193.0.22.1 0 100 0 1800 690 560 ?*>i 193.0.16.1 0 100 0 1800 690 560 ?* 198.92.72.24 0 1878 704 701 560 ?* i13.0.0.0 193.0.22.1 0 100 0 1800 690 200 ?*>i 193.0.16.1 0 100 0 1800 690 200 ?* 198.92.72.24 0 1878 704 701 200 ?* i15.0.0.0 193.0.22.1 0 100 0 1800 174 ?*>i 193.0.16.1 0 100 0 1800 174 ?* i16.0.0.0 193.0.22.1 0 100 0 1800 701 i*>i 193.0.16.1 0 100 0 1800 701 i* 198.92.72.24 0 1878 704 701 idescribes significant fields shown in the display.
Table 19-7 Show IP BGP Field Descriptions
The following is sample output from the show ip bgp command when you specify longer-prefixes:
Router# show ip bgp 198.92.0.0 255.255.0.0 longer-prefixesBGP table version is 1738, local router ID is 198.92.72.24Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path*> 198.92.0.0 198.92.72.30 8896 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.1.0 198.92.72.30 8796 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.11.0 198.92.72.30 42482 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.14.0 198.92.72.30 8796 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.15.0 198.92.72.30 8696 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.16.0 198.92.72.30 1400 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.17.0 198.92.72.30 1400 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.18.0 198.92.72.30 8876 32768 ?* 198.92.72.30 0 109 108 ?*> 198.92.19.0 198.92.72.30 8876 32768 ?* 198.92.72.30 0 109 108 ?show ip bgp cidr-only
To display routes with nonnatural network masks (classless interdomain routing [CIDR]), use the show ip bgp cidr-only privileged EXEC command.
show ip bgp cidr-only
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show ip bgp cidr-only command:
Router# show ip bgp cidr-onlyBGP table version is 220, local router ID is 198.92.73.131Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path*> 192.0.0.0/8 198.92.72.24 0 1878 ?*> 198.92.0.0/16 198.92.72.30 0 108 ?show ip bgp community
To display routes that belong to specified BGP communities, use the show ip bgp community EXEC command.
show ip bgp community community-number [exact]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output from the show ip bgp community command:
router#show ip bgp community 111:12345 internetBGP table version is 10, local router ID is 224.0.0.10Status codes: s suppressed, d damped, h history, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path*> 2.2.2.2/32 158.43.222.2 0 0 222 ?*> 111.0.0.0 158.43.222.2 0 0 222 ?*> 158.43.0.0 158.43.222.2 0 0 222 ?*> 158.43.44.44/32 158.43.222.2 0 0 222 ?* 158.43.222.0/24 158.43.222.2 0 0 222 i*> 172.17.240.0/21 158.43.222.2 0 0 222 ?*> 192.168.212.0 158.43.222.2 0 0 222 i*> 203.9.1.0 158.43.222.2 0 0 222 ?describes significant fields shown in the display.
Table 19-8 Show IP BGP Community Field Descriptions
show ip bgp community-list
To display routes that are permitted by the BGP community list, use the show ip bgp community-list EXEC command.
show ip bgp community-list community-list-number [exact]
Syntax Description
community-list-number
Community list number in the range from 1 through 99.
exact
(Optional) Displays only routes that have an exact match.
Command Mode
EXEC
Sample Display
The following is sample output of the show ip bgp community-list command:
Router# show ip bgp community-list 20BGP table version is 716977, local router ID is 193.0.32.1Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path* i3.0.0.0 193.0.22.1 0 100 0 1800 1239 ?*>i 193.0.16.1 0 100 0 1800 1239 ?* i6.0.0.0 193.0.22.1 0 100 0 1800 690 568 ?*>i 193.0.16.1 0 100 0 1800 690 568 ?* i7.0.0.0 193.0.22.1 0 100 0 1800 701 35 ?*>i 193.0.16.1 0 100 0 1800 701 35 ?* 198.92.72.24 0 1878 704 701 35 ?* i8.0.0.0 193.0.22.1 0 100 0 1800 690 560 ?*>i 193.0.16.1 0 100 0 1800 690 560 ?* 198.92.72.24 0 1878 704 701 560 ?* i13.0.0.0 193.0.22.1 0 100 0 1800 690 200 ?*>i 193.0.16.1 0 100 0 1800 690 200 ?* 198.92.72.24 0 1878 704 701 200 ?* i15.0.0.0 193.0.22.1 0 100 0 1800 174 ?*>i 193.0.16.1 0 100 0 1800 174 ?* i16.0.0.0 193.0.22.1 0 100 0 1800 701 i*>i 193.0.16.1 0 100 0 1800 701 i* 198.92.72.24 0 1878 704 701 idescribes significant fields shown in the display.
Table 19-9 Show IP BGP Community List Field Descriptions
show ip bgp filter-list
To display routes that conform to a specified filter list, use the show ip bgp filter-list privileged EXEC command.
show ip bgp filter-list access-list-number
Syntax Description
access-list-number
Number of an autonomous system path access list. It can be a number from 1 through 199.
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show ip bgp filter-list command:
Router# show ip bgp filter-list 2BGP table version is 1738, local router ID is 198.92.72.24Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path* 198.92.0.0 198.92.72.30 0 109 108 ?* 198.92.1.0 198.92.72.30 0 109 108 ?* 198.92.11.0 198.92.72.30 0 109 108 ?* 198.92.14.0 198.92.72.30 0 109 108 ?* 198.92.15.0 198.92.72.30 0 109 108 ?* 198.92.16.0 198.92.72.30 0 109 108 ?* 198.92.17.0 198.92.72.30 0 109 108 ?* 198.92.18.0 198.92.72.30 0 109 108 ?* 198.92.19.0 198.92.72.30 0 109 108 ?* 198.92.24.0 198.92.72.30 0 109 108 ?* 198.92.29.0 198.92.72.30 0 109 108 ?* 198.92.30.0 198.92.72.30 0 109 108 ?* 198.92.33.0 198.92.72.30 0 109 108 ?* 198.92.35.0 198.92.72.30 0 109 108 ?* 198.92.36.0 198.92.72.30 0 109 108 ?* 198.92.37.0 198.92.72.30 0 109 108 ?* 198.92.38.0 198.92.72.30 0 109 108 ?* 198.92.39.0 198.92.72.30 0 109 108 ?show ip bgp inconsistent-as
To display routes with inconsistent originating autonomous systems, use the show ip bgp inconsistent-as privileged EXEC command.
show ip bgp inconsistent-as
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show ip bgp inconsistent-as command:
Router# show ip bgp inconsistent-asBGP table version is 87, local router ID is 172.19.82.53Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path* 11.0.0.0 171.69.232.55 0 0 300 88 90 99 ?*> 171.69.232.52 2222 0 400 ?* 171.69.0.0 171.69.232.55 0 0 300 90 99 88 200 ?*> 171.69.232.52 2222 0 400 ?* 200.200.199.0 171.69.232.55 0 0 300 88 90 99 ?*> 171.69.232.52 2222 0 400 ?show ip bgp neighbors
To display information about the TCP and BGP connections to neighbors, use the show ip bgp neighbors EXEC command.
show ip bgp neighbors [address [routes | paths]]
Syntax Description
Command Mode
EXEC
Sample Displays
The following is sample output from the show ip bgp neighbors command:
Router# show ip bgp neighborsBGP neighbor is 131.108.6.68, remote AS 10, external linkBGP version 3, remote router ID 131.108.6.68BGP state = Established, table version = 22, up for 0:00:13Last read 0:00:12, hold time is 180, keepalive interval is 60 secondsReceived 24 messages, 0 notificationsSent 28 messages, 4 notificationsConnections established 1; dropped 0Connection state is ESTAB, I/O status: 1, unread input bytes: 0Local host: 131.108.6.69, 12288 Foreign host: 131.108.6.68, 179Enqueued packets for retransmit: 0, input: 0, saved: 0Event Timers (current time is 835828):Timer: Retrans TimeWait AckHold SendWnd KeepAliveStarts: 20 0 18 0 0Wakeups: 1 0 2 0 0Next: 0 0 0 0 0iss: 60876 snduna: 62649 sndnxt: 62649 sndwnd: 1872irs: 95187024 rcvnxt: 95188733 rcvwnd: 1969 delrcvwnd: 271SRTT: 364 ms, RTTO: 1691 ms, RTV: 481 ms, KRTT: 0 msminRTT: 4 ms, maxRTT: 340 ms, ACK hold: 300 msFlags: higher precedenceDatagrams (max data segment is 1450 bytes):Rcvd: 36 (out of order: 0), with data: 18, total data bytes: 1708Sent: 40 (retransmit: 1), with data: 36, total data bytes: 1817describes the fields shown in the display.
Table 19-10 Show IP BGP Neighbors Field Descriptions
The remainder of the display describes the status of the underlying TCP connection.
The following is sample output from the show ip bgp neighbors command when you specify the routes keyword:
Router# show ip bgp neighbors 198.41.177.210 routesBGP table version is 212136, local router ID is 131.108.5.225Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path*> 163.179.0.0 192.41.177.210 100 2551 i* 192.203.50.0 192.41.177.210 100 2551 ?*> 199.183.0.0/16 192.41.177.210 100 2551 idescribes the fields shown in the display.
Table 19-11 Show IP BGP Neighbors Routes Field Descriptions
show ip bgp paths
To display all the BGP paths in the database, use the show ip bgp paths EXEC command.
show ip bgp paths
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip bgp paths command:
Router# show ip bgp pathsAddress Hash Refcount Metric Path0x297A9C 0 2 0 i0x30BF84 1 0 0 702 701 ?0x2F7BC8 2 235 0 ?0x2FA1D8 3 0 0 702 701 idescribes significant fields shown in the display.
Table 19-12 Show IP BGP Paths Field Descriptions
show ip bgp peer-group
To display information about BGP peer groups, use the show ip bgp peer-group EXEC command.
show ip bgp peer-group [tag] [summary]
Syntax Description
tag
(Optional) Displays information about that specific peer group.
summary
(Optional) Displays a summary of the status of all the members of a peer group.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip bgp peer-group command:
Router# show ip bgp peer-group0 internalBGP neighbor is internal, peer-group leaderBGP version 4Minimum time between advertisement runs is 5 secondsIncoming update AS path filter list is 2Outgoing update AS path filter list is 1Route map for outgoing advertisements is set-medshow ip bgp regexp
To display routes matching the regular expression, use the show ip bgp regexp privileged EXEC command.
show ip bgp regexp regular-expression
Syntax Description
Command Mode
Privileged EXEC
Sample Display
Router# show ip bgp regexp 108$BGP table version is 1738, local router ID is 198.92.72.24Status codes: s suppressed, * valid, > best, i - internalOrigin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path* 198.92.0.0 198.92.72.30 0 109 108 ?* 198.92.1.0 198.92.72.30 0 109 108 ?* 198.92.11.0 198.92.72.30 0 109 108 ?* 198.92.14.0 198.92.72.30 0 109 108 ?* 198.92.15.0 198.92.72.30 0 109 108 ?* 198.92.16.0 198.92.72.30 0 109 108 ?* 198.92.17.0 198.92.72.30 0 109 108 ?* 198.92.18.0 198.92.72.30 0 109 108 ?* 198.92.19.0 198.92.72.30 0 109 108 ?* 198.92.24.0 198.92.72.30 0 109 108 ?* 198.92.29.0 198.92.72.30 0 109 108 ?* 198.92.30.0 198.92.72.30 0 109 108 ?* 198.92.33.0 198.92.72.30 0 109 108 ?* 198.92.35.0 198.92.72.30 0 109 108 ?* 198.92.36.0 198.92.72.30 0 109 108 ?* 198.92.37.0 198.92.72.30 0 109 108 ?* 198.92.38.0 198.92.72.30 0 109 108 ?* 198.92.39.0 198.92.72.30 0 109 108 ?show ip bgp summary
To display the status of all BGP connections, use the show ip bgp summary EXEC command.
show ip bgp summary
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip bgp summary command:
Router# show ip bgp summaryBGP table version is 717029, main routing table version 71702919073 network entries (37544 paths) using 3542756 bytes of memory691 BGP path attribute entries using 57200 bytes of memoryNeighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State193.0.16.1 4 1755 32642 2973 717029 0 0 1:27:11193.0.17.1 4 1755 4790 2973 717029 0 0 1:27:51193.0.18.1 4 1755 7722 3024 717029 0 0 1:28:13193.0.19.1 4 1755 0 0 0 0 0 2d02 Active193.0.20.1 4 1755 3673 3049 717029 0 0 2:50:10193.0.21.1 4 1755 3741 3048 717029 0 0 12:24:43193.0.22.1 4 1755 33129 3051 717029 0 0 12:24:48193.0.23.1 4 1755 0 0 0 0 0 2d02 Active193.0.24.1 4 1755 0 0 0 0 0 2d02 Active193.0.25.1 4 1755 0 0 0 0 0 2d02 Active193.0.26.1 4 1755 0 0 0 0 0 2d02 Active193.0.27.1 4 1755 4269 3049 717029 0 0 12:39:33193.0.28.1 4 1755 3037 3050 717029 0 0 2:08:15198.92.72.24 4 1878 11635 13300 717028 0 0 0:50:39describes significant fields shown in the display.
Table 19-13 Show IP BGP Summary Field Descriptions
show ip dvmrp route
To display the contents of the DVMRP routing table, use the show ip dvmrp route EXEC command.
show ip dvmrp route [ip-address]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output of the show ip dvmrp route command:
Router# show ip dvmrp routeDVMRP Routing Table - 1 entry171.68.0.0/16 [100/11] uptime 07:55:50, expires 00:02:52via 137.39.3.93, Tunnel3describes the fields shown in the display
Table 19-14 Show IP DVMRP Route Field Descriptions
Related Command
show ip egp
To display statistics about EGP connections and neighbors, use the show ip egp EXEC command.
show ip egp
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip egp command:
Router# show ip egpLocal autonomous system is 109EGP Neighbor FAS/LAS State SndSeq RcvSeq Hello Poll j/k Flags10.3.0.27 1/109 IDLE 625 61323 60 180 0 Perm, Act* 10.2.0.37 1/109 UP 12:29 250 14992 60 180 3 Perm, Act* 10.7.0.63 1/109 UP 1d19 876 10188 60 180 4 Perm, Passdescribes the fields shown in the display.
Table 19-15 Show IP EGP Field Descriptions
show ip eigrp neighbors
To display the neighbors discovered by Enhanced IGRP, use the show ip eigrp neighbors EXEC command.
show ip eigrp neighbors [type number]
Syntax Description
Command Mode
EXEC
Usage Guidelines
Use the show ip eigrp neighbors command to determine when neighbors become active and inactive. It is also useful for debugging certain types of transport problems.
Sample Display
The following is sample output from the show ip eigrp neighbors command:
Router# show ip eigrp neighborsIP-EIGRP Neighbors for process 77Address Interface Holdtime Uptime Q Seq SRTT RTO(secs) (h:m:s) Count Num (ms) (ms)160.89.81.28 Ethernet1 13 0:00:41 0 11 4 20160.89.80.28 Ethernet0 14 0:02:01 0 10 12 24160.89.80.31 Ethernet0 12 0:02:02 0 4 5 20explains the fields in the output.
Table 19-16 Show IP EIGRP Neighbors Field Descriptions
show ip eigrp topology
To display the Enhanced IGRP topology table, use the show ip eigrp topology EXEC command.
show ip eigrp topology [autonomous-system-number | [[ip-address] mask]]
Syntax Description
Command Mode
EXEC
Usage Guidelines
Use the show ip eigrp topology command to determine DUAL states and to debug possible DUAL problems.
Sample Display
The following is sample output from the show ip eigrp topology command:
Router# show ip eigrp topologyIP-EIGRP Topology Table for process 77Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,r - Reply statusP 160.89.90.0 255.255.255.0, 2 successors, FD is 0via 160.89.80.28 (46251776/46226176), Ethernet0via 160.89.81.28 (46251776/46226176), Ethernet1via 160.89.80.31 (46277376/46251776), Ethernet0P 160.89.81.0 255.255.255.0, 1 successors, FD is 307200via Connected, Ethernet1via 160.89.81.28 (307200/281600), Ethernet1via 160.89.80.28 (307200/281600), Ethernet0via 160.89.80.31 (332800/307200), Ethernet0explains the fields in the output.
Table 19-17 Show IP EIGRP Topology Field Descriptions
show ip eigrp traffic
To display the number of Enhanced IGRP packets sent and received, use the show ip eigrp traffic EXEC command.
show ip eigrp traffic [autonomous-system-number]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output from the show ip eigrp traffic command:
Router# show ip eigrp trafficIP-EIGRP Traffic Statistics for process 77Hellos sent/received: 218/205Updates sent/received: 7/23Queries sent/received: 2/0Replies sent/received: 0/2Acks sent/received: 21/14describes the fields that might be shown in the display.
Table 19-18 Show IP EIGRP Traffic Field Descriptions
show ip igmp groups
To display the multicast groups that are directly connected to the router and that were learned via IGMP, use the show ip igmp groups EXEC command.
show ip igmp groups [group-name | group-address | type number]
Syntax Description
Command Mode
EXEC
Usage Guidelines
If you omit all optional arguments, the show ip igmp groups command displays by group address and interface type and number all directly connected multicast groups.
Sample Display
The following is sample output from the show ip igmp groups command:
Router# show ip igmp groupsIGMP Connected Group MembershipGroup Address Interface Uptime Expires Last Reporter224.0.255.1 Ethernet0 18:51:41 0:02:15 198.92.37.192224.2.226.60 Ethernet0 1:51:31 0:02:17 198.92.37.192224.2.127.255 Ethernet0 18:51:45 0:02:17 198.92.37.192226.2.2.2 Ethernet1 18:51:47 never 0.0.0.0224.2.0.1 Ethernet0 18:51:43 0:02:14 198.92.37.192225.2.2.2 Ethernet0 18:51:43 0:02:21 198.92.37.33225.2.2.2 Ethernet1 18:51:47 never 0.0.0.0225.2.2.4 Ethernet0 18:18:02 0:02:20 198.92.37.192225.2.2.4 Ethernet1 18:23:32 0:02:55 198.92.36.128describes the fields shown in the display.
Table 19-19 Show IP IGMP Groups Field Descriptions
Related Command
show ip igmp interface
To display multicast-related information about an interface, use the show ip igmp interface EXEC command.
show ip igmp interface [type number]
Syntax Description
Command Mode
EXEC
Usage Guidelines
If you omit the optional arguments, the show ip igmp interface command displays information about all interfaces.
This command also displays information about dynamically learned DVMRP routers on the interface.
Sample Display
The following is sample output from the show ip igmp interface command:
Router# show ip igmp interfaceEthernet0 is up, line protocol is upInternet address is 198.92.37.6, subnet mask is 255.255.255.0IGMP is enabled on interfaceIGMP query interval is 60 secondsInbound IGMP access group is not setMulticast routing is enabled on interfaceMulticast TTL threshold is 0Multicast designated router (DR) is 198.92.37.33No multicast groups joinedEthernet1 is up, line protocol is upInternet address is 198.92.36.129, subnet mask is 255.255.255.0IGMP is enabled on interfaceIGMP query interval is 60 secondsInbound IGMP access group is not setMulticast routing is enabled on interfaceMulticast TTL threshold is 0Multicast designated router (DR) is 198.92.36.131Multicast groups joined: 225.2.2.2 226.2.2.2Tunnel0 is up, line protocol is upInternet address is 10.1.37.2, subnet mask is 255.255.0.0IGMP is enabled on interfaceIGMP query interval is 60 secondsInbound IGMP access group is not setMulticast routing is enabled on interfaceMulticast TTL threshold is 0No multicast groups joineddescribes the fields shown in the display.
Table 19-20 Show IP IGMP Interface Field Descriptions
Ethernet0 is up, line protocol is up
Interface type, number, and status.
Internet address is...
subnet mask is...Internet address of the interface and subnet mask being applied to the interface, as specified with the ip address command.
IGMP is enabled on interface
Indicates whether IGMP has been enabled on the interface with the ip pim command.
IGMP query interval is 60 seconds
Interval at which the router sends PIM router-query messages, as specified with the ip igmp query-interval command.
Inbound IGMP access group is not set
Indicates whether an IGMP access group has been configured with the ip igmp access-group command.
Multicast routing is enabled on interface
Indicates whether multicast routing has been enabled on the interface with the ip pim command.
Multicast TTL threshold is 0
Packet time-to-threshold, as specified with the ip multicast ttl-threshold command.
Multicast designated router (DR) is...
IP address of the designated router for this LAN segment (subnet).
Multicast groups joined:
No multicast groups joinedIndicates whether this interface is a member of any multicast groups and, if so, lists the IP addresses of the groups.
Related Commands
A dagger (†) indicates that the command is documented in another chapter.
ip address †
ip igmp access-group
ip igmp query-interval
ip multicast ttl-threshold
ip pimshow ip irdp
To display IRDP values, use the show ip irdp EXEC command.
show ip irdp
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip irdp command:
Router# show ip irdpEthernet 0 has router discovery enabledAdvertisements will occur between every 450 and 600 seconds.Advertisements are valid for 1800 seconds.Default preference will be 100.--More--Serial 0 has router discovery disabled--More--Ethernet 1 has router discovery disabledAs the display shows, show ip irdp output indicates whether router discovery has been configured for each router interface, and lists the values of router discovery configurables for those interfaces on which router discovery has been enabled. Explanations for the less self-evident lines of output in the display follow.
Advertisements will occur between every 450 and 600 seconds.Indicates the configured minimum and maximum advertising interval for the interface.
Advertisements are valid for 1800 seconds.Indicates the configured holdtime values for the interface.
Default preference will be 100.Indicates the configured (or in this case default) preference value for the interface.
show ip local policy
To display the route map used for local policy routing, if any, use the show ip local policy EXEC command.
show ip local policy
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
Sample Display
The following is sample output from the show ip local policy command:
Router# show ip local policyLocal policy routing is enabled, using route map equalroute-map equal, permit, sequence 10Match clauses:length 150 200Set clauses:ip next-hop 10.10.11.254Policy routing matches: 0 packets, 0 bytesroute-map equal, permit, sequence 20Match clauses:ip address (access-lists): 101Set clauses:ip next-hop 10.10.11.14Policy routing matches: 2 packets, 172 bytesRelated Commands
ip local policy route-map
match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hopshow ip mcache
To display the contents of the IP fast switching cache, use the show ip mcache EXEC command.
show ip mcache [group [source]]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output from the show ip mcache command. This entry shows a specific source (wrn-source 204.62.246.73) sending to the World Radio Network group (224.2.143.24).
Router> show ip mcache wrn wrn-sourceIP Multicast Fast-Switching Cache(204.62.246.73/32, 224.2.143.24), Fddi0, Last used: 00:00:00Ethernet0 MAC Header: 01005E028F1800000C1883D30800Ethernet1 MAC Header: 01005E028F1800000C1883D60800Ethernet2 MAC Header: 01005E028F1800000C1883D40800Ethernet3 MAC Header: 01005E028F1800000C1883D70800describes the significant fields in the display.
Table 19-21 Show IP Mcache Field Descriptions
show ip mroute
To display the contents of the IP multicast routing table, use the show ip mroute EXEC command.
show ip mroute [group] [source] [summary] [count] [active kbps]
Syntax Description
Default
The show ip mroute command displays all groups and sources.
The show ip mroute active command displays all sources sending at a rate greater than or equal to 4 kbps.Command Mode
EXEC
Usage Guidelines
If you omit all optional arguments and keywords, the show ip mroute command displays all entries in the IP multicast routing table.
The router populates the multicast routing table by creating source, group (S,G) entries from star, group (*,G) entries. The star refers to all source addresses, the "S" refers to a single source address, and the "G" is the destination multicast group address. In creating (S,G) entries, the router uses the best path to that destination group found in the unicast routing table (that is, via Reverse Path Forwarding [RPF]).
Sample Displays
The following is sample output from the show ip mroute command for a router operating is dense mode. This command displays the contents of the IP multicast routing table for the multicast group named cbone-audio.
Router> show ip mroute cbone-audioIP Multicast Routing TableFlags: D - Dense, S - Sparse, C - Connected, L - Local, P - PrunedR - RP-bit set, F - Register flag, T - SPT-bit setTimers: Uptime/ExpiresInterface state: Interface, Next-Hop, State/Mode(*, 224.0.255.1), uptime 0:57:31, expires 0:02:59, RP is 0.0.0.0, flags: DCIncoming interface: Null, RPF neighbor 0.0.0.0, DvmrpOutgoing interface list:Ethernet0, Forward/Dense, 0:57:31/0:02:52Tunnel0, Forward/Dense, 0:56:55/0:01:28(198.92.37.100/32, 224.0.255.1), uptime 20:20:00, expires 0:02:55, flags: CIncoming interface: Tunnel0, RPF neighbor 10.20.37.33, DvmrpOutgoing interface list:Ethernet0, Forward/Dense, 20:20:00/0:02:52The following is sample output from the show ip mroute command for a router operating in sparse mode:
Router# show ip mrouteIP Multicast Routing TableFlags: D - Dense, S - Sparse, C - Connected, L - Local, P - PrunedR - RP-bit set, F - Register flag, T - SPT-bit setTimers: Uptime/ExpiresInterface state: Interface, Next-Hop, State/Mode(*, 224.0.255.3), uptime 5:29:15, RP is 198.92.37.2, flags: SCIncoming interface: Tunnel0, RPF neighbor 10.3.35.1, DvmrpOutgoing interface list:Ethernet0, Forward/Sparse, 5:29:15/0:02:57(198.92.46.0/24, 224.0.255.3), uptime 5:29:15, expires 0:02:59, flags: CIncoming interface: Tunnel0, RPF neighbor 10.3.35.1Outgoing interface list:Ethernet0, Forward/Sparse, 5:29:15/0:02:57explains the fields shown in the displays.
Table 19-22 Show IP Mroute Field Descriptions
Related Command
show ip ospf
To display general information about OSPF routing processes, use the show ip ospf EXEC command.
show ip ospf [process-id]
Syntax Description
process-id
(Optional) Process ID. If this argument is included, only information for the specified routing process is included.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip ospf command when entered without a specific OSPF process ID:
Router# show ip ospfRouting Process "ospf 201" with ID 192.42.110.200Supports only single TOS(TOS0) routeIt is an area border and autonomous system boundary routerSummary Link update interval is 0:30:00 and the update due in 0:16:26External Link update interval is 0:30:00 and the update due in 0:16:27Redistributing External Routes from,igrp 200 with metric mapped to 2, includes subnets in redistributionrip with metric mapped to 2igrp 2 with metric mapped to 100igrp 32 with metric mapped to 1Number of areas in this router is 3Area 192.42.110.0Number of interfaces in this area is 1Area has simple password authenticationSPF algorithm executed 6 timesArea ranges areLink State Update Interval is 0:30:00 and due in 0:16:55Link State Age Interval is 0:20:00 and due in 0:06:55describes significant fields shown in the display.
Table 19-23 Show IP OSPF Field Descriptions
show ip ospf border-routers
To display the internal OSPF routing table entries to an Area Border Router (ABR) and Autonomous System Boundary Router (ASBR), use the show ip ospf border-routers privileged EXEC command.
show ip ospf border-routers
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show ip ospf border-routers command:
Router# show ip ospf border-routersOSPF Process 109 internal Routing TableDestination Next Hop Cost Type Rte Type Area SPF No160.89.97.53 144.144.1.53 10 ABR INTRA 0.0.0.3 3160.89.103.51 160.89.96.51 10 ABR INTRA 0.0.0.3 3160.89.103.52 160.89.96.51 20 ASBR INTER 0.0.0.3 3160.89.103.52 144.144.1.53 22 ASBR INTER 0.0.0.3 3describes the fields shown in the display.
Table 19-24 Show IP OSPF Border-routers Field Descriptions
show ip ospf database
Use the show ip ospf database EXEC command to display lists of information related to the OSPF database for a specific router. The various forms of this command deliver information about different OSPF link state advertisements.
show ip ospf [process-id area-id] database
show ip ospf [process-id area-id] database [router] [link-state-id]
show ip ospf [process-id area-id] database [network] [link-state-id]
show ip ospf [process-id area-id] database [summary] [link-state-id]
show ip ospf [process-id area-id] database [asb-summary] [link-state-id]
show ip ospf [process-id] database [external] [link-state-id]
show ip ospf [process-id area-id] database [database-summary]Command Mode
EXEC
Syntax Description
When entered with the optional keyword router, network, summary, asb-summary, external, or database-summary, different displays result. Examples and brief descriptions of each form follow.
Sample Display of Show IP OSPF Database with No Arguments or Keywords
The following is sample output from the show ip ospf database command when no arguments or keywords are used:
Router# show ip ospf databaseOSPF Router with id(190.20.239.66) (Process ID 300)Displaying Router Link States(Area 0.0.0.0)Link ID ADV Router Age Seq# Checksum Link count155.187.21.6 155.187.21.6 1731 0x80002CFB 0x69BC 8155.187.21.5 155.187.21.5 1112 0x800009D2 0xA2B8 5155.187.1.2 155.187.1.2 1662 0x80000A98 0x4CB6 9155.187.1.1 155.187.1.1 1115 0x800009B6 0x5F2C 1155.187.1.5 155.187.1.5 1691 0x80002BC 0x2A1A 5155.187.65.6 155.187.65.6 1395 0x80001947 0xEEE1 4155.187.241.5 155.187.241.5 1161 0x8000007C 0x7C70 1155.187.27.6 155.187.27.6 1723 0x80000548 0x8641 4155.187.70.6 155.187.70.6 1485 0x80000B97 0xEB84 6Displaying Net Link States(Area 0.0.0.0)Link ID ADV Router Age Seq# Checksum155.187.1.3 192.20.239.66 1245 0x800000EC 0x82EDisplaying Summary Net Link States(Area 0.0.0.0)Link ID ADV Router Age Seq# Checksum155.187.240.0 155.187.241.5 1152 0x80000077 0x7A05155.187.241.0 155.187.241.5 1152 0x80000070 0xAEB7155.187.244.0 155.187.241.5 1152 0x80000071 0x95CBdescribes significant fields shown in the display.
Table 19-25 Show IP OSPF Database Field Descriptions
Sample Display Using Show IP OSPF Database ASB-Summary
The following is sample output from the show ip ospf database asb-summary command when no optional arguments are specified:
Router# show ip ospf database asb-summaryOSPF Router with id(190.20.239.66) (Process ID 300)Displaying Summary ASB Link States(Area 0.0.0.0)LS age: 1463Options: (No TOS-capability)LS Type: Summary Links(AS Boundary Router)Link State ID: 155.187.245.1 (AS Boundary Router address)Advertising Router: 155.187.241.5LS Seq Number: 80000072Checksum: 0x3548Length: 28Network Mask: 0.0.0.0 TOS: 0 Metric: 1describes significant fields shown in the display.
Table 19-26 Show IP OSPF Database ASB-Summary Field Descriptions
Sample Display Using Show IP OSPF Database External
The following is sample output from the show ip ospf database external command when no optional arguments are specified:
Router# show ip ospf database externalOSPF Router with id(190.20.239.66) (Process ID 300)Displaying AS External Link StatesLS age: 280Options: (No TOS-capability)LS Type: AS External LinkLink State ID: 143.105.0.0 (External Network Number)Advertising Router: 155.187.70.6LS Seq Number: 80000AFDChecksum: 0xC3ALength: 36Network Mask: 255.255.0.0Metric Type: 2 (Larger than any link state path)TOS: 0Metric: 1Forward Address: 0.0.0.0External Route Tag: 0describes significant fields shown in the display.
Table 19-27 Show IP OSPF Database External Field Descriptions
Sample Display Using Show IP OSPF Database Network
The following is sample output from the show ip ospf database network command when no optional arguments are specified:
Router# show ip ospf database networkOSPF Router with id(190.20.239.66) (Process ID 300)Displaying Net Link States(Area 0.0.0.0)LS age: 1367Options: (No TOS-capability)LS Type: Network LinksLink State ID: 155.187.1.3 (address of Designated Router)Advertising Router: 190.20.239.66LS Seq Number: 800000E7Checksum: 0x1229Length: 52Network Mask: 255.255.255.0Attached Router: 190.20.239.66Attached Router: 155.187.241.5Attached Router: 155.187.1.1Attached Router: 155.187.54.5Attached Router: 155.187.1.5describes significant fields shown in the display.
Table 19-28 Show IP OSPF Database Network Field Descriptions
Sample Display Using Show IP OSPF Database Router
The following is sample output from the show ip ospf database router command when no optional arguments are specified:
Router# show ip ospf database routerOSPF Router with id(190.20.239.66) (Process ID 300)Displaying Router Link States(Area 0.0.0.0)LS age: 1176Options: (No TOS-capability)LS Type: Router LinksLink State ID: 155.187.21.6Advertising Router: 155.187.21.6LS Seq Number: 80002CF6Checksum: 0x73B7Length: 120AS Boundary Router155 Number of Links: 8Link connected to: another Router (point-to-point)(link ID) Neighboring Router ID: 155.187.21.5(Link Data) Router Interface address: 155.187.21.6Number of TOS metrics: 0TOS 0 Metrics: 2describes significant fields shown in the display.
Table 19-29 Show IP OSPF Database Router Field Descriptions
Sample Display Using Show IP OSPF Database Summary
The following is sample output from show ip ospf database summary command when no optional arguments are specified:
Router# show ip ospf database summaryOSPF Router with id(190.20.239.66) (Process ID 300)Displaying Summary Net Link States(Area 0.0.0.0)LS age: 1401Options: (No TOS-capability)LS Type: Summary Links(Network)Link State ID: 155.187.240.0 (summary Network Number)Advertising Router: 155.187.241.5LS Seq Number: 80000072Checksum: 0x84FFLength: 28Network Mask: 255.255.255.0 TOS: 0 Metric: 1describes significant fields shown in the display.
Table 19-30 Show IP OSPF Database Summary Field Descriptions
Sample Display Using Show IP OSPF Database Database-Summary
The following is sample output from show ip ospf database database-summary command when no optional arguments are specified:
Router# show ip ospf database database-summaryOSPF Router with ID (172.19.65.21) (Process ID 1)Area ID Router Network Sum-Net Sum-ASBR Subtotal Delete Maxage202 1 0 0 0 1 0 0AS External 0 0 0Total 1 0 0 0 1describes significant fields shown in the display.
Table 19-31 Show IP OSPF Database Database-Summary Field Descriptions
show ip ospf interface
To display OSPF-related interface information, use the show ip ospf interface EXEC command.
show ip ospf interface [type number]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output from the show ip ospf interface command when Ethernet 0 is specified:
Router# show ip ospf interface ethernet 0Ethernet 0 is up, line protocol is upInternet Address 131.119.254.202, Mask 255.255.255.0, Area 0.0.0.0AS 201, Router ID 192.77.99.1, Network Type BROADCAST, Cost: 10Transmit Delay is 1 sec, State OTHER, Priority 1Designated Router id 131.119.254.10, Interface address 131.119.254.10Backup Designated router id 131.119.254.28, Interface addr 131.119.254.28Timer intervals configured, Hello 10, Dead 60, Wait 40, Retransmit 5Hello due in 0:00:05Neighbor Count is 8, Adjacent neighbor count is 2Adjacent with neighbor 131.119.254.28 (Backup Designated Router)Adjacent with neighbor 131.119.254.10 (Designated Router)describes significant fields shown in the display.
Table 19-32 Show IP OSPF Interface Ethernet 0 Field Descriptions
show ip ospf neighbor
To display OSPF-neighbor information on a per-interface basis, use the show ip ospf neighbor EXEC command.
show ip ospf neighbor [type number] [neighbor-id] detail
Syntax Description
type
(Optional) Interface type.
number
(Optional) Interface number.
neighbor-id
(Optional) Neighbor ID.
detail
Displays all neighbors given in detail (list all neighbors).
Command Mode
EXEC
Sample Displays
The following is sample output from the show ip ospf neighbor command showing a single line of summary information for each neighbor:
Router# show ip ospf neighborID Pri State Dead Time Address Interface199.199.199.137 1 FULL/DR 0:00:31 160.89.80.37 Ethernet0192.31.48.1 1 FULL/DROTHER 0:00:33 192.31.48.1 Fddi0192.31.48.200 1 FULL/DROTHER 0:00:33 192.31.48.200 Fddi0199.199.199.137 5 FULL/DR 0:00:33 192.31.48.189 Fddi0The following is sample output showing summary information about the neighbor that matches the neighbor ID:
Router# show ip ospf neighbor 199.199.199.137Neighbor 199.199.199.137, interface address 160.89.80.37In the area 0.0.0.0 via interface Ethernet0Neighbor priority is 1, State is FULLOptions 2Dead timer due in 0:00:32Link State retransmission due in 0:00:04Neighbor 199.199.199.137, interface address 192.31.48.189In the area 0.0.0.0 via interface Fddi0Neighbor priority is 5, State is FULLOptions 2Dead timer due in 0:00:32Link State retransmission due in 0:00:03If you specify the interface along with the Neighbor ID, the router displays the neighbors that match the neighbor ID on the interface, as in the following sample display:
Router# show ip ospf neighbor e 0 199.199.199.137Neighbor 199.199.199.137, interface address 160.89.80.37In the area 0.0.0.0 via interface Ethernet0Neighbor priority is 1, State is FULLOptions 2Dead timer due in 0:00:37Link State retransmission due in 0:00:04You can also specify the interface without the neighbor ID to show all neighbors on the specified interface, as in the following sample display:
Router# show ip ospf neighbor f 0ID Pri State Dead Time Address Interface192.31.48.1 1 FULL/DROTHER 0:00:33 192.31.48.1 Fddi0192.31.48.200 1 FULL/DROTHER 0:00:32 192.31.48.200 Fddi0199.199.199.137 5 FULL/DR 0:00:32 192.31.48.189 Fddi0The following is sample output from the show ip ospf neighbor detail command:
Router# show ip ospf neighbor detailNeighbor 160.89.96.54, interface address 160.89.96.54In the area 0.0.0.3 via interface Ethernet0Neighbor priority is 1, State is FULLOptions 2Dead timer due in 0:00:38Neighbor 160.89.103.52, interface address 160.89.103.52In the area 0.0.0.0 via interface Serial0Neighbor priority is 1, State is FULLOptions 2Dead timer due in 0:00:31describes the fields shown in the displays.
Table 19-33 Show IP OSPF Neighbor Field Descriptions
show ip ospf request-list
To display a list of all link state advertisements (LSAs) requested by a router, use the show ip ospf request-list EXEC command.
show ip ospf request-list [nbr] [intf] [intf-nbr]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.2.
Sample Displays
The following is sample output from the show ip ospf request-list command:
router# show ip ospf request-list se0OSPF Router with ID (200.1.1.11) (Process ID 1)Neighbor 200.1.1.12, interface Serial0 address 144.1.1.12Type LS ID ADV RTR Seq NO Age Checksum1 200.1.1.12 200.1.1.12 0x8000020D 8 0x6572show ip ospf retransmission-list
To display a list of all link state advertisements (LSAs) waiting to be retransmitted, use the show ip ospf retransmission-list EXEC command.
show ip ospf retransmission-list [nbr] [intf] [intf-nbr]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.2.
Sample Displays
The following is sample output from the show ip ospf retransmission-list command:
Router# show ip ospf retransmission-list se0OSPF Router with ID (200.1.1.12) (Process ID 1)Neighbor 200.1.1.11, interface Serial0 address 144.1.1.11Link state retransmission due in 3764 msec, Queue length 2Type LS ID ADV RTR Seq NO Age Checksum1 200.1.1.12 200.1.1.12 0x80000210 0 0xB196show ip ospf virtual-links
To display parameters about and the current state of OSPF virtual links, use the show ip ospf virtual-links EXEC command.
show ip ospf virtual-links
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
The information displayed by show ip ospf virtual-links is useful in debugging OSPF routing operations.
Sample Display
The following is sample output from the show ip ospf virtual-links command:
Router# show ip ospf virtual-linksVirtual Link to router 160.89.101.2 is upTransit area 0.0.0.1, via interface Ethernet0, Cost of using 10Transmit Delay is 1 sec, State POINT_TO_POINTTimer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5Hello due in 0:00:08Adjacency State FULLdescribes significant fields shown in the display.
Table 19-34 Show IP OSPF Virtual-links Field Descriptions
show ip pim interface
To display information about interfaces configured for PIM, use the show ip pim interface EXEC command.
show ip pim interface [type number] [count]
Syntax Description
type
(Optional) Interface type.
number
(Optional) Interface number.
count
(Optional) Displays the number of IP multicast packets received and sent on the interface.
Command Mode
EXEC
Usage Guidelines
This command works only on interfaces that are configured for PIM.
Sample Display
The following is sample output from the show ip pim interface command:
Router# show ip pim interfaceAddress Interface Mode Neighbor Query DRCount Interval198.92.37.6 Ethernet0 Dense 2 30 198.92.37.33198.92.36.129 Ethernet1 Dense 2 30 198.92.36.13110.1.37.2 Tunnel0 Dense 1 30 0.0.0.0The following is sample output from the show ip pim interface command with a count:
Router# show ip pim interface countAddress Interface FS Mpackets In/Out171.69.121.35 Ethernet0 * 548305239/13744856171.69.121.35 Serial0.33 * 8256/67052912198.92.12.73 Serial0.1719 * 219444/862191describes the fields shown in the display.
Table 19-35 Show IP PIM Interface Field Description
Related Commands
show ip pim neighbor
To list the PIM neighbors discovered by the router, use the show ip pim neighbor EXEC command.
show ip pim neighbor [type number]
Syntax Description
Command Mode
EXEC
Usage Guidelines
Use this command to determine which routers on the LAN are configured for PIM.
Sample Display
The following is sample output from the show ip pim neighbor command:
Router# show ip pim neighborPIM Neighbor TableNeighbor Address Interface Uptime Expires Mode198.92.37.2 Ethernet0 17:38:16 0:01:25 Dense198.92.37.33 Ethernet0 17:33:20 0:01:05 Dense (DR)198.92.36.131 Ethernet1 17:33:20 0:01:08 Dense (DR)198.92.36.130 Ethernet1 18:56:06 0:01:04 Dense10.1.22.9 Tunnel0 19:14:59 0:01:09 Densedescribes the fields shown in the display.
Table 19-36 Show IP PIM Neighbor Field Description
Related Command
show ip pim rp
To display the rendezvous point (RP) routers associated with a sparse-mode multicast group, use the show ip pim rp EXEC command.
show ip pim rp [group-name | group-address]
Syntax Description
Command Mode
EXEC
Sample Displays
The following is sample output from the show ip pim rp command from a router that is not an RP:
Router1# show ip pim rpGroup: 224.2.127.255, number of RPs: 1RP address: 198.92.37.2, state: Up, uptime 0:01:25, expires in 0:03:04The following is sample output from the show ip pim rp command from a router that is an RP:
Router2# show ip pim rpGroup: 224.2.127.255, number of RPs: 1RP address: 198.92.37.2, state: Up, next RP-reachable in 0:01:01explains the fields shown in the displays.
Table 19-37 Show IP PIM RP Field Description
Related Command
show ip policy
To display the route map used for policy routing, use the show ip policy EXEC command.
show ip policy
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.1.
Sample Displays
The following is sample output from the show ip policy command:
Router# show ip policyInterface Route maplocal equalEthernet0 equalThe following is sample output from the show route-map command, which relates to the preceding sample display:
Router# show route-maproute-map equal, permit, sequence 10Match clauses:length 150 200Set clauses:ip next-hop 10.10.11.254Policy routing matches: 0 packets, 0 bytesroute-map equal, permit, sequence 20Match clauses:ip address (access-lists): 101Set clauses:ip next-hop 10.10.11.14Policy routing matches: 144 packets, 15190 bytesRelated Commands
match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hopshow ip protocols
To display the parameters and current state of the active routing protocol process, use the show ip protocols EXEC command.
show ip protocols
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
The information displayed by show ip protocols is useful in debugging routing operations. Information in the Routing Information Sources field of the show ip protocols output can help you identify a router suspected of delivering bad routing information.
Sample Displays
The following is sample output from the show ip protocols command, showing IGRP processes:
Router# show ip protocolsRouting Protocol is "igrp 109"Sending updates every 90 seconds, next due in 44 secondsInvalid after 270 seconds, hold down 280, flushed after 630Outgoing update filter list for all interfaces is not setIncoming update filter list for all interfaces is not setDefault networks flagged in outgoing updatesDefault networks accepted from incoming updatesIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0IGRP maximum hopcount 100IGRP maximum metric variance 1Redistributing: igrp 109Routing for Networks:198.92.72.0Routing Information Sources:Gateway Distance Last Update198.92.72.18 100 0:56:41198.92.72.19 100 6d19198.92.72.22 100 0:55:41198.92.72.20 100 0:01:04198.92.72.30 100 0:01:29Distance: (default is 100)Routing Protocol is "bgp 1878"Sending updates every 60 seconds, next due in 0 secondsOutgoing update filter list for all interfaces is 1Incoming update filter list for all interfaces is not setRedistributing: igrp 109IGP synchronization is disabledAutomatic route summarization is enabledNeighbor(s):Address FiltIn FiltOut DistIn DistOut Weight RouteMap192.108.211.17 1192.108.213.89 1198.6.255.13 1198.92.72.18 1198.92.72.19198.92.84.17 1Routing for Networks:192.108.209.0192.108.211.0198.6.254.0Routing Information Sources:Gateway Distance Last Update198.92.72.19 20 0:05:28Distance: external 20 internal 200 local 200describes significant fields shown in the display.
Table 19-38 Show IP Protocols Field Descriptions
The following is sample output from the show ip protocols command, showing Enhanced IGRP processes:
Router# show ip protocolsRouting Protocol is "eigrp 77"Outgoing update filter list for all interfaces is not setIncoming update filter list for all interfaces is not setRedistributing: eigrp 77Automatic network summarization is in effectRouting for Networks:160.89.0.0Routing Information Sources:Gateway Distance Last Update160.89.81.28 90 0:02:36160.89.80.28 90 0:03:04160.89.80.31 90 0:03:04Distance: internal 90 external 170describes the fields that might be shown in the display.
Table 19-39 Show IP Protocols Field Descriptions
The following is sample output from the show ip protocols command, showing IS-IS processes:
Router# show ip protocolsRouting Protocol is "isis"Sending updates every 0 secondsInvalid after 0 seconds, hold down 0, flushed after 0Outgoing update filter list for all interfaces is not setIncoming update filter list for all interfaces is not setRedistributing: isisAddress Summarization:NoneRouting for Networks:Serial0Routing Information Sources:Distance: (default is 115)show ip route
Use the show ip route EXEC command to display the current state of the routing table.
show ip route [address [mask] [longer-prefixes]] | [protocol [process-id]]
Syntax Description
Command Mode
EXEC
Sample Displays
The following is sample output from the show ip route command when entered without an address:
Router# show ip routeCodes: I - IGRP derived, R - RIP derived, O - OSPF derivedC - connected, S - static, E - EGP derived, B - BGP derived* - candidate default route, IA - OSPF inter area routeE1 - OSPF external type 1 route, E2 - OSPF external type 2 routeGateway of last resort is 131.119.254.240 to network 129.140.0.0O E2 150.150.0.0 [160/5] via 131.119.254.6, 0:01:00, Ethernet2E 192.67.131.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2O E2 192.68.132.0 [160/5] via 131.119.254.6, 0:00:59, Ethernet2O E2 130.130.0.0 [160/5] via 131.119.254.6, 0:00:59, Ethernet2E 128.128.0.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2E 129.129.0.0 [200/129] via 131.119.254.240, 0:02:22, Ethernet2E 192.65.129.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2E 131.131.0.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2E 192.75.139.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2E 192.16.208.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2E 192.84.148.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2E 192.31.223.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2E 192.44.236.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2E 140.141.0.0 [200/129] via 131.119.254.240, 0:02:22, Ethernet2E 141.140.0.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2The following is sample output that includes some IS-IS Level 2 routes learned:
Router# show ip routeCodes: I - IGRP derived, R - RIP derived, O - OSPF derivedC - connected, S - static, E - EGP derived, B - BGP derivedi - IS-IS derived* - candidate default route, IA - OSPF inter area routeE1 - OSPF external type 1 route, E2 - OSPF external type 2 routeL1 - IS-IS level-1 route, L2 - IS-IS level-2 routeGateway of last resort is not set160.89.0.0 is subnetted (mask is 255.255.255.0), 3 subnetsC 160.89.64.0 255.255.255.0 is possibly down,routing via 0.0.0.0, Ethernet0i L2 160.89.67.0 [115/20] via 160.89.64.240, 0:00:12, Ethernet0i L2 160.89.66.0 [115/20] via 160.89.64.240, 0:00:12, Ethernet0describes significant fields shown in these two displays.
Table 19-40 Show IP Route Field Descriptions
When you specify that you want information about a specific network displayed, more detailed statistics are shown. The following is sample output from the show ip route command when entered with the address 131.119.0.0.
Router# show ip route 131.119.0.0Routing entry for 131.119.0.0 (mask 255.255.0.0)Known via "igrp 109", distance 100, metric 10989Tag 0Redistributing via igrp 109Last update from 131.108.35.13 on TokenRing0, 0:00:58 agoRouting Descriptor Blocks:* 131.108.35.13, from 131.108.35.13, 0:00:58 ago, via TokenRing0Route metric is 10989, traffic share count is 1Total delay is 45130 microseconds, minimum bandwidth is 1544 KbitReliability 255/255, minimum MTU 1500 bytesLoading 2/255, Hops 4describes significant fields shown in the display.
Table 19-41 Show IP Route with Address Field Descriptions
The following is sample output using the longer-prefixes keyword. When the longer-prefixes keyword is included, the address and mask pair becomes the prefix, and any address that matches that prefix is displayed. Therefore, multiple addresses are displayed.
In the following example, the logical AND operation is performed on the source address 128.0.0.0 and the mask 128.0.0.0, resulting in 128.0.0.0. Each destination in the routing table is also logically ANDed with the mask and compared to that result of 128.0.0.0. Any destinations that fall into that range are displayed in the output.
Router# show ip route 128.0.0.0 128.0.0.0 longer-prefixesCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGPD - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter areaE1 - OSPF external type 1, E2 - OSPF external type 2, E - EGPi - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate defaultGateway of last resort is not setS 134.134.0.0 is directly connected, Ethernet0S 131.131.0.0 is directly connected, Ethernet0S 129.129.0.0 is directly connected, Ethernet0S 128.128.0.0 is directly connected, Ethernet0S 198.49.246.0 is directly connected, Ethernet0S 192.160.97.0 is directly connected, Ethernet0S 192.153.88.0 is directly connected, Ethernet0S 192.76.141.0 is directly connected, Ethernet0S 192.75.138.0 is directly connected, Ethernet0S 192.44.237.0 is directly connected, Ethernet0S 192.31.222.0 is directly connected, Ethernet0S 192.16.209.0 is directly connected, Ethernet0S 144.145.0.0 is directly connected, Ethernet0S 140.141.0.0 is directly connected, Ethernet0S 139.138.0.0 is directly connected, Ethernet0S 129.128.0.0 is directly connected, Ethernet0172.19.0.0 255.255.255.0 is subnetted, 1 subnetsC 172.19.64.0 is directly connected, Ethernet0171.69.0.0 is variably subnetted, 2 subnets, 2 masksC 171.69.232.32 255.255.255.240 is directly connected, Ethernet0S 171.69.0.0 255.255.0.0 is directly connected, Ethernet0Router#Related Commands
A dagger (†) indicates that the command is documented in another chapter.
show interfaces tunnel †
show ip route summaryshow ip route summary
To display the current state of the routing table, use the show ip route summary EXEC command.
show ip route summary
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Sample Display
The following is sample output from the show ip route summary command:
Router# show ip route summaryRoute Source Networks Subnets Overhead Memory (bytes)connected 0 3 126 360static 1 2 126 360igrp 109 747 12 31878 91080internal 3 360Total 751 17 32130 92160Router#describes the fields shown in the display:
Table 19-42 Show IP Route Summary Field Descriptions
Related Command
show ip route supernets-only
To display information about supernets, use the show ip route supernets-only privileged EXEC command.
show ip route supernets-only
Command Mode
Privileged EXEC
Sample Display
The following is sample output from the show ip route supernets-only command:
Router# show ip route supernets-onlyCodes: I - IGRP derived, R - RIP derived, O - OSPF derivedC - connected, S - static, E - EGP derived, B - BGP derivedi - IS-IS derived, D - EIGRP derived* - candidate default route, IA - OSPF inter area routeE1 - OSPF external type 1 route, E2 - OSPF external type 2 routeL1 - IS-IS level-1 route, L2 - IS-IS level-2 routeEX - EIGRP external routeGateway of last resort is not setB 198.92.0.0 (mask is 255.255.0.0) [20/0] via 198.92.72.30, 0:00:50B 192.0.0.0 (mask is 255.0.0.0) [20/0] via 198.92.72.24, 0:02:50Router#This display shows supernets only; it does not show subnets.
show ip rpf
To display how IP multicast routing does Reverse-Path Forwarding (RPF), use the show ip rpf EXEC command.
show ip rpf source-address-or-name
Syntax Description
source-address-or-name
Source name or address of the host for which the RPF information is displayed.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
The router can Reverse-Path Forward from multiple routing tables (that is, the unicast routing table, DVMRP routing table, or static mroutes). This command tells you where the information is retrieved from.
Sample Display
The following is sample output of the show ip rpf command:
Router # show ip rpf 171.69.10.13RPF information for sj-eng-mbone.cisco.com (171.69.10.13)RPF interface: BRI0RPF neighbor: eng-isdn-pri3.cisco.com (171.69.121.10)RPF route/mask: 171.69.0.0/255.255.0.0RPF type: unicastdescribes the significant fields in the display.
Table 19-43 Show IP RPF Field Descriptions
show ip sd
To display the contents of the session directory cache, use the show ip sd EXEC command.
show ip sd [group | "session-name" | detail]
Syntax Description
Command Mode
EXEC
Usage Guidelines
If the router is configured to be a member of 224.2.127.255 (the default session directory group), it will cache session directory announcements. If no arguments are used, a sorted list of session names is displayed.
Sample Display
The following is sample output from the show ip sd command, showing each session that the router has learned:
Router> show ip sdSD Cache - 22 entries*cisco: CABONE Audio*cisco: CABONE Video*cisco: CABONE Whiteboard*cisco: CBONE audio*cisco: CBONE video*cisco: CBONE Whiteboard*cisco: CCIE Audio*cisco:Eng Services Ops Review*cisco:Scamp's Managers MeetingA3TESTakiAPLtestarch-nusBharat Dave-ETHcboneCERN - LHCCcisco: Beta FolksDBDECUS '95: Marc Andreessen (audio)DECUS '95: Marc Andreessen (vic/h261)Digital Unix MulticastDSTC Fun with whiteboardThe following is sample output from the show ip sd detail command:
Router# show ip sd detailSD Cache - 3 entriesSession Name: *cisco: CABONE AudioDescription: cisco Customer Advocacy Audio ChannelGroup: 224.0.255.128, ttl: 16Lifetime: from 00:00:24 PDT May 9 1995 until 00:00:24 PDT May 23 1995Created by: bpinsky@on-tap.cisco.com (171.68.225.179)Media: audio 55557 2688--More--Session Name: *cisco: CABONE VideoDescription: cisco Customer Advocacy Video ChannelGroup: 224.0.255.130, ttl: 16Lifetime: from 00:00:56 PDT May 9 1995 until 00:00:56 PDT May 23 1995Created by: bpinsky@on-tap.cisco.com (171.68.225.179)Media: video 62676 63933--More--Session Name: *cisco: CABONE WhiteboardDescription: cisco Customer Advocacy WhiteboardGroup: 224.0.255.129, ttl: 16Lifetime: from 00:00:30 PDT May 9 1995 until 00:00:30 PDT May 23 1995Created by: bpinsky@on-tap.cisco.com (171.68.225.179)Media: whiteboard 43411 14736describes the significant fields in the display.
Table 19-44 Show IP SD Field Descriptions
show isis database
To display the IS-IS link state database, use the show isis database EXEC command.
show isis database [level-1] [level-2] [l1] [l2] [detail] [lspid]
Syntax Description
Command Mode
EXEC
Usage Guidelines
Each of the options shown in brackets for this command can be entered in an arbitrary string within the same command entry. For example, the following are both valid command specifications and provide the same output: show isis database detail l2 and show isis database l2 detail.
Sample Display
The following is sample output from the show isis database command when it is specified with no options or as show isis database l1 l2:
Router# show isis databaseIS-IS Level-1 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL0000.0C00.0C35.00-00 0x0000000C 0x5696 792 0/0/00000.0C00.40AF.00-00* 0x00000009 0x8452 1077 1/0/00000.0C00.62E6.00-00 0x0000000A 0x38E7 383 0/0/00000.0C00.62E6.03-00 0x00000006 0x82BC 384 0/0/00800.2B16.24EA.00-00 0x00001D9F 0x8864 1188 1/0/00800.2B16.24EA.01-00 0x00001E36 0x0935 1198 1/0/0IS-IS Level-2 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL0000.0C00.0C35.03-00 0x00000005 0x04C8 792 0/0/00000.0C00.3E51.00-00 0x00000007 0xAF96 758 0/0/00000.0C00.40AF.00-00* 0x0000000A 0x3AA9 1077 0/0/0describes significant fields shown in the display.
Table 19-45 Show IS-IS Database Field Descriptions
Sample Display Using Show IS-IS Database Detail
The following is sample output from the show isis database detail command.
Router# show isis database detailIS-IS Level-1 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL0000.0C00.0C35.00-00 0x0000000C 0x5696 325 0/0/0Area Address: 47.0004.004D.0001Area Address: 39.0001Metric: 10 IS 0000.0C00.62E6.03Metric: 0 ES 0000.0C00.0C35--More--0000.0C00.40AF.00-00* 0x00000009 0x8452 608 1/0/0Area Address: 47.0004.004D.0001Metric: 10 IS 0800.2B16.24EA.01Metric: 10 IS 0000.0C00.62E6.03Metric: 0 ES 0000.0C00.40AFIS-IS Level-2 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL0000.0C00.0C35.03-00 0x00000005 0x04C8 317 0/0/0Metric: 0 IS 0000.0C00.0C35.00--More--0000.0C00.3E51.00-00 0x00000009 0xAB98 1182 0/0/0Area Address: 39.0004Metric: 10 IS 0000.0C00.40AF.00Metric: 10 IS 0000.0C00.3E51.05As the output shows, in addition to the information displayed with show isis database, the show isis database detail command displays the contents of each LSP.
describes the fields shown in the display.
Table 19-46 Show IS-IS Database Detail Field Descriptions
Sample Display Using Show IS-IS Database Detail Displaying IP Addresses
The following is additional sample output from the show isis database detail command.This is a Level 2 LSP. The area address 39.0001 is the address of the area in which the router resides.
Router# show isis database detail l2IS-IS Level-2 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL0000.0C00.1111.00-00* 0x00000006 0x4DB3 1194 0/0/0Area Address: 39.0001NLPID: 0x81 0xCCIP Address: 160.89.64.17Metric: 10 IS 0000.0C00.1111.09Metric: 10 IS 0000.0C00.1111.08Metric: 10 IP 160.89.65.0 255.255.255.0Metric: 10 IP 160.89.64.0 255.255.255.0Metric: 0 IP-External 10.0.0.0 255.0.0.0describes the fields shown in the display.
Table 19-47 Show IS-IS Database Detail Field Descriptions
show route-map
To display configured route-maps, use the show route-map EXEC command.
show route-map [map-name]
Syntax Description
Command Mode
EXEC
Sample Display
The following is sample output from the show route-map command:
Router# show route-maproute-map foo, permit, sequence 10Match clauses:tag 1 2Set clauses:metric 5route-map foo, permit, sequence 20Match clauses:tag 3 4Set clauses:metric 6describes the fields shown in the display:
Table 19-48 Show Route-map Field Descriptions
Related Commands
summary-address
Use the summary-address router configuration command to create aggregate addresses for IS-IS or OSPF. The no summary-address command restores the default.
summary-address address mask {level-1 | level-1-2 | level-2}
no summary-address address mask {level-1 | level-1-2 | level-2}Syntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
Multiple groups of addresses can be summarized for a given level. Routes learned from other routing protocols can also be summarized. The metric used to advertise the summary is the smallest metric of all the more specific routes. This command helps reduce the size of the routing table.
Using this command for OSPF causes an OSPF Autonomous System Boundary Router (ASBR) to advertise one external route as an aggregate for all redistributed routes that are covered by the address. For OSPF, this command summarizes only routes from other routing protocols that are being redistributed into OSPF. Use the area range command for route summarization between OSPF areas.
Example for IS-IS
In the following example, summary address 10.1.0.0 includes address 10.1.1, 10.1.2, 10.1.3, 10.1.4, and so forth. Only the address 10.1.0.0 is advertised in an IS-IS Level 1 Link State PDU.
summary-address 10.1.0.0 255.255.0.0 level-1Example for OSPF
In the following example, summary address 10.1.0.0 includes address 10.1.1.0, 10.1.2.0, 10.1.3.0, and so forth. Only the address 10.1.0.0 is advertised in an external link state advertisement.
summary-address 10.1.0.0 255.255.0.0Related Command
synchronization
To enable the synchronization between BGP and your IGP, use the synchronization router configuration command. To enable a router to advertise a network route without waiting for the IGP, use the no form of this command.
synchronization
no synchronizationSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Router configuration
Usage Guidelines
Usually, a BGP speaker does not advertise a route to an external neighbor unless that route is local or exists in the IGP. The no synchronization command allows a router to advertise a network route without waiting for the IGP. This feature allows routers within an autonomous system to have the route before BGP makes it available to other autonomous systems.
Use synchronization if there are routers in the autonomous system that do not speak BGP.
Example
The following example enables the router to advertise a network route without waiting for the IGP:
router bgp 120no synchronizationtable-map
To modify metric and tag values when the IP routing table is updated with BGP learned routes, use the table-map router configuration command. To disable this function, use the no form of the command.
table-map route-map-name
no table-map route-map-nameSyntax Description
Default
Disabled
Command Mode
Router configuration
Usage Guidelines
This command adds the route map name defined by the route-map command to the IP routing table. This command is used to set the tag name and the route metric to implement redistribution.
You can use match clauses of route maps in the table-map command. IP access list, autonomous system paths, and next-hop match clauses are supported.
Example
In the following example, the router is configured to automatically compute the tag value for the BGP learned routes and to update the IP routing table.
route-map tagmatch as path 10set automatic-tag!router bgp 100table-map tagRelated Commands
match as-path
match ip address
match ip next-hop
route-maptimers basic (EGP, RIP, IGRP)
To adjust EGP, RIP, or IGRP network timers, use the timers basic router configuration command. To restore the default timers, use the no form of this command.
timers basic update invalid holddown flush [sleeptime]
no timers basicSyntax Description
Defaults
EGP
N/A
1080
N/A
1200
N/A
RIP
30
180
180
240
N/A
IGRP
90
270
280
630
0
Command Mode
Router configuration
Usage Guidelines
The basic timing parameters for IGRP, EGP, and RIP are adjustable. Since these routing protocols are executing a distributed, asynchronous routing algorithm, it is important that these timers be the same for all routers in the network.
Note
Examples
In the following example, updates are broadcast every 5 seconds. If a router is not heard from in 15 seconds, the route is declared unusable. Further information is suppressed for an additional 15 seconds. At the end of the suppression period, the route is flushed from the routing table.
router igrp 109timers basic 5 15 15 30Note that by setting a short update period, you run the risk of congesting slow-speed serial lines; however, this is not a big concern on faster-speed Ethernets and T1-rate serial lines. Also, if you have many routes in your updates, you can cause the routers to spend an excessive amount of time processing updates.
When the timers basic command is used with EGP, the update time and holddown time are ignored. For example, the commands that follow will set the invalid time for EGP to 100 seconds and the flush time to 200 seconds.
router egp 47timers basic 0 100 0 200timers bgp
To adjust BGP network timers, use the timers bgp router configuration command. To reset the BGP timing defaults, use the no form of this command.
timers bgp keepalive holdtime
no timers bgpSyntax Description
Defaults
keepalive: 60 seconds
holdtime: 180 secondsCommand Mode
Router configuration
Example
The following example changes the keepalive timer to 70 seconds and the holdtime timer to 210 seconds:
timers bgp 70 210Related Commands
clear ip bgp
router bgp
show ip bgptimers egp
To adjust EGP Hello and polltime network timers, use the timers egp router configuration command. The no form of this command resets the EGP timing defaults.
timers egp hello polltime
no timers egpSyntax Description
Defaults
hello: 60 seconds
polltime: 180 secondsCommand Mode
Router configuration
Usage Guidelines
To change the invalid time or flush time for EGP routes, use the timers basic router configuration command.
Example
The following example changes the EGP timers to 2 minutes and 5 minutes, respectively:
timers egp 120 300Related Commands
router egp
show ip egp
timers basic (EGP, RIP, IGRP)timers spf
To configure the delay time between when OSPF receives a topology change and when it starts a Shortest Path First (SPF) calculation, and the hold time between two consecutive SPF calculations, use the timers spf router configuration command. To return to the default timer values, use the no form of this command.
timers spf spf-delay spf-holdtime
no timers spf spf-delay spf-holdtimeSyntax Description
Defaults
spf-delay: 5 seconds
spf-holdtime: 10 secondsCommand Mode
Router configuration
Usage Guidelines
Setting the delay and hold time low causes routing to switch to the alternate path more quickly in the event of a failure. However, it consumes more CPU processing time.
Example
The following example changes the delay to 10 seconds and the hold time to 20 seconds:
timers spf 10 20traffic-share
To control how traffic is distributed among routes when there are multiple routes for the same destination network that have different costs, use the traffic-share router configuration command. To disable this function, use the no form of the command.
traffic-share {balanced | min}
[no] traffic share {balanced | min}Syntax Description
balanced
Distributes traffic proportionately to the ratios of the metrics.
min
Uses routes that have minimum costs.
Default
Traffic is distributed proportionately to the ratios of the metrics.
Command Mode
Router configuration
Usage Guidelines
This command applies to IGRP and Enhanced IGRP routing protocols only. With the default setting, routes that have higher metrics represent less-preferable routes and get less traffic. Configuring traffic-share min causes the router to only divide traffic among the routes with the best metric. Other routes will remain in the routing table, but will receive no traffic.
Example
In the following example, only routes of minimum cost will be used:
router igrp 5traffic-share minvalidate-update-source
To have the router to validate the source IP address of incoming routing updates for RIP and IGRP routing protocols, use the validate-update-source router configuration command. To disable this function, use the no form of this command.
validate-update-source
no validate-update-sourceSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Router configuration
Usage Guidelines
This command is only applicable to RIP and IGRP. The router ensures that the source IP address of incoming routing updates is on the same IP network as one of the addresses defined for the receiving interface.
Disabling split horizon on the incoming interface will also cause the system to perform this validation check.
For unnumbered IP interfaces (interfaces configured as ip unnumbered), no checking is performed.
Example
In the following example, the router is configured to not perform validation checks on the source IP address of incoming RIP updates:
router ripnetwork 128.105.0.0no validate-update-sourcevariance
To control load balancing in an Enhanced IGRP-based internetwork, use the variance router configuration command. To reset the variance to the default value, use the no form of this command.
variance multiplier
no varianceSyntax Description
multiplier
Metric value used for load balancing. It can be a value from 1 to 128. The default is 1, which means equal-cost load balancing.
Default
1 (equal-cost load balancing)
Command Mode
Router configuration
Usage Guidelines
Setting a variance value lets the router determine the feasibility of a potential route. A route is feasible if the next router in the path is closer to the destination than the current router and if the metric for the entire path is within the variance. Only paths that are feasible can be used for load balancing and included in the routing table.
If the following two conditions are met, the route is deemed feasible and can be added to the routing table:
1
2
Example
The following example sets a variance value of 4:
router igrp 109variance 4
Posted: Tue Oct 12 16:48:33 PDT 2004
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