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I through R
- ip authentication key-chain eigrp
- ip authentication mode eigrp
- ipv6 authentication mode eigrp
- ip bandwidth-percent eigrp
- ip hello-interval eigrp
- ip hold-time eigrp
- ip next-hop-self eigrp
- ip split-horizon eigrp
- ip summary-address eigrp
- ipv6 authentication key-chain eigrp
- ipv6 bandwidth-percent eigrp
- ipv6 eigrp
- ipv6 hello-interval eigrp
- ipv6 hold-time eigrp
- ipv6 next-hop-self eigrp
- ipv6 router eigrp
- ipv6 split-horizon eigrp
- ipv6 summary-address eigrp
- log-neighbor-changes (EIGRP)
- log-neighbor-changes (IPv6 EIGRP)
- log-neighbor-warnings
- match extcommunity
- match tag list
- maximum-prefix
- metric holddown
- metric maximum-hops
- metric rib-scale
- metric weights (EIGRP)
- neighbor (EIGRP)
- neighbor description
- neighbor maximum-prefix (EIGRP)
- network (EIGRP)
- next-hop-self
- nsf (EIGRP)
- offset-list (EIGRP)
- passive-interface (EIGRP)
- redistribute eigrp
- redistribute maximum-prefix (EIGRP)
- remote-neighbors source (EIGRP)
- router eigrp
- route-tag list
- route-tag notation
ip authentication key-chain eigrp
To enable authentication of Enhanced Interior Gateway Routing Protocol (EIGRP) packets, use the ip authentication key-chain eigrpcommand in interface configuration mode. To disable such authentication, use the no form of this command.
ip authentication key-chain eigrp as-number key-chain
no ip authentication key-chain eigrp as-number key-chain
Syntax Description
as-number
Autonomous system number to which the authentication applies.
key-chain
Name of the authentication key chain.
Command History
Release
Modification
11.2F
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode.
Examples
The following example applies authentication to autonomous system 2 and identifies a key chain named SPORTS:
ip authentication key-chain eigrp 2 SPORTSRelated Commands
Command
Description
accept-lifetime
Sets the time period during which the authentication key on a key chain is received as valid.
ip authentication mode eigrp
Specifies the type of authentication used in EIGRP packets.
key
Identifies an authentication key on a key chain.
key chain
Enables authentication of routing protocols.
key-string (authentication)
Specifies the authentication string for a key.
send-lifetime
Sets the time period during which an authentication key on a key chain is valid to be sent.
ip authentication mode eigrp
To specify the type of authentication used in Enhanced Interior Gateway Routing Protocol (EIGRP) packets, use the ip authentication mode eigrpcommand in interface configuration mode. To disable that type of authentication, use the no form of this command.
Syntax Description
as-number
Autonomous system number.
md5
Keyed Message Digest 5 ( MD5) authentication.
Command History
Release
Modification
11.2F
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode.
Usage Guidelines
Configure authentication to prevent unapproved sources from introducing unauthorized or false routing messages. When authentication is configured, an MD5 keyed digest is added to each EIGRP packet in the specified autonomous system.
Examples
The following example configures the interface to use MD5 authentication in EIGRP packets in autonomous system 10:
ip authentication mode eigrp 10 md5Related Commands
Command
Description
accept-lifetime
Sets the time period during which the authentication key on a key chain is received as valid.
ip authentication key-chain eigrp
Enables authentication of EIGRP packets.
key
Identifies an authentication key on a key chain.
key chain
Enables authentication of routing protocols.
key-string (authentication)
Specifies the authentication string for a key.
send-lifetime
Sets the time period during which an authentication key on a key chain is valid to be sent.
ipv6 authentication mode eigrp
To specify the type of authentication used in Enhanced Interior Gateway Routing Protocol (EIGRP) packets for IPv6, use the ipv6 authentication mode eigrpcommand in interface configuration mode. To disable the type of authentication, use the no form of this command.
Usage Guidelines
Use the ipv6 authentication mode eigrpcommand to configure authentication to prevent unapproved sources from introducing unauthorized or false routing messages. When authentication is configured, an MD5 keyed digest is added to each EIGRP for IPv6 packet in the specified autonomous system.
Examples
The following example configures the interface to use MD5 authentication in EIGRP for IPv6 packets in autonomous system 1:
Router(config-if)# ipv6 authentication mode eigrp 1 md5Related Commands
Command
Description
accept-lifetime
Sets the time period during which the authentication key on a key chain is received as valid.
ipv6 authentication key-chain eigrp
Enables authentication of EIGRP packets for IPv6.
key
Identifies an authentication key on a key chain.
key chain
Enables authentication of routing protocols.
key-string (authentication)
Specifies the authentication string for a key.
send-lifetime
Sets the time period during which an authentication key on a key chain is valid to be sent.
ip bandwidth-percent eigrp
To configure the percentage of bandwidth that may be used by Enhanced Interior Gateway Routing Protocol (EIGRP) on an interface, use the ip bandwidth-percent eigrpcommand in interface configuration mode. To restore the default value, use the no form of this command.
Syntax Description
as-number
Autonomous system number.
percent
Percent of bandwidth that EIGRP may use.
Command History
Release
Modification
11.2
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode.
Usage Guidelines
EIGRP will use up to 50 percent of the bandwidth of a link, as defined by the bandwidth interface configuration command. This command may be used if some other fraction of the bandwidth is desired. Note that values greater than 100 percent may be configured. The configuration option may be useful if the bandwidth is set artificially low for other reasons.
ip hello-interval eigrp
To configure the hello interval for an Enhanced Interior Gateway Routing Protocol (EIGRP) process, use the ip hello-interval eigrp command in interface configuration mode. To restore the default value, use the no form of this command.
Syntax Description
as-number
Autonomous system number.
seconds
Hello interval (in seconds). The range is from 1 to 65535.
Command Default
The hello interval for low-speed, nonbroadcast multiaccess (NBMA) networks is 60 seconds and 5 seconds for all other networks.
Command History
Release
Modification
10.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode.
Usage Guidelines
The default of 60 seconds applies only to low-speed, 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 EIGRP, Frame Relay and Switched Multimegabit Data Service (SMDS) networks may 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.
ip hold-time eigrp
To configure the hold time for an Enhanced Interior Gateway Routing Protocol (EIGRP) process, use the ip hold-time eigrp command in interface configuration mode. To restore the default value, use the no form of this command.
Syntax Description
as-number
Autonomous system number.
seconds
Hold time (in seconds). The range is from 1 to 65535.
Command Default
The EIGRP hold time is 180 seconds for low-speed, nonbroadcast multiaccess (NBMA) networks and 15 seconds for all other networks.
Command History
Release
Modification
10.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode.
Usage Guidelines
On very congested and large networks, the default hold time might not be sufficient time for all routers and access servers 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 this 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, NBMA media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command.
ip next-hop-self eigrp
To enable the Enhanced Interior Gateway Routing Protocol (EIGRP) to advertise routes with the local outbound interface address as the next hop, use the ip next-hop-self eigrp command in interface configuration mode or virtual network interface mode. To instruct EIGRP to use the received next hop instead of the local outbound interface address, use the no form of this command.
ip next-hop-self eigrp autonomous-system-number
no ip next-hop-self eigrp autonomous-system-number [ no-ecmp-mode ]
Command History
Release
Modification
12.3
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. This command was made available in virtual network interface configuration mode.
Cisco IOS XE Release 3.5S
This command was modified. The no-ecmp-mode keyword was added.
15.2(1)S
This command was modified. The no-ecmp-mode keyword was added.
15.2(3)T
This command was modified. The no-ecmp-mode keyword was added.
Usage Guidelines
EIGRP, by default, sets the next-hop value to the local outbound interface address for routes that it is advertising, even when advertising those routes back out of the same interface on which they were learned. To change this default, you must use the no ip next-hop-self eigrp interface configuration command to instruct EIGRP to use the received next-hop value when advertising these routes. Following are some exceptions to this guideline:
- If your topology does not require spoke-to-spoke dynamic tunnels, you need not configure the no ip next-hop-self eigrp command.
- If your topology requires spoke-to-spoke dynamic tunnels, you must use process switching on the tunnel interface of spoke devices. Otherwise, you will need to use a different routing protocol over Dynamic Multipoint VPN (DMVPN).
The no-ecmp-mode option is an enhancement to the no ip next-hop-self eigrp command. When this option is enabled, all routes to a network in the EIGRP table are evaluated to check whether routes advertised from an interface were learned on the same interface. If a route advertised by an interface was learned on the same interface, the no ip next-hop-self eigrp configuration is honored and the received next hop is used to advertise this route. Disabling the IP next-hop self functionality is primarily useful in DMVPN spoke-to-spoke topologies.
Examples
The following example shows how to change the default next-hop value in IPv4 classic mode configurations by disabling the ip next-hop-self functionality and configuring EIGRP to use the received next-hop value to advertise routes:
Device(config)# interface tun 0 Device(config-if)# no ip next-hop-self eigrp 101 no-ecmp-modeip split-horizon eigrp
To enable Enhanced Interior Gateway Routing Protocol (EIGRP) split horizon, use the ip split-horizon eigrp command in interface configuration mode. To disable split horizon, use the no form of this command.
Command History
Release
Modification
10.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode.
Usage Guidelines
For networks that include links over X.25 packet-switched networks (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 and access servers in any relevant multicast groups on that network.
NoteIn general, we recommend 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 and access servers in any relevant multicast groups on that network.
ip summary-address eigrp
To configure address summarization for the Enhanced Interior Gateway Routing Protocol (EIGRP) on a specified interface, use the ip summary-address eigrp command in interface configuration or virtual network interface configuration mode. To disable the configuration, use the no form of this command.
ip summary-address eigrp as-number ip-address mask [admin-distance] [ leak-map name ]
no ip summary-address eigrp as-number ip-address mask
Syntax Description
Command Modes
Interface configuration (config-if)
Virtual network interface configuration (config-if-vnet)
Command History
Release
Modification
10.0
This command was introduced.
12.0(7)T
This command was modified. The admin-distance argument was added.
12.3(14)T
This command was modified. The leak-map keyword was added.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
Cisco IOS XE Release 3.2S
This command was modified. Support was added for this command in virtual network interface configuration mode. The admin-distance argument was removed. Use the summary-metric command to configure the administrative distance.
12.2(33)SXJ
This command was modified. The summary address is not advertised to the peer if the administrative distance is configured as 255.
15.0(1)SY
This command was modified. Support was added for this command in virtual network interface configuration mode.
15.1(1)SG
This command was integrated into Cisco IOS Release 15.1(1)SG.
Cisco IOS XE Release 3.3SG
This command was integrated into Cisco IOS XE Release 3.3SG.
Usage Guidelines
The ip summary-address eigrp command is used to configure interface-level address summarization. EIGRP summary routes are given an administrative-distance value of 5. The administrative-distance metric is used to advertise a summary without installing it in the routing table.
By default, EIGRP summarizes subnet routes to the network level. The no auto-summary command can be entered to configure the subnet-level summarization.
The summary address is not advertised to the peer if the administrative distance is configured as 255.
EIGRP Support for Leaking Routes
Configuring the leak-map keyword allows a component route that would otherwise be suppressed by the manual summary to be advertised. Any component subset of the summary can be leaked. A route map and access list must be defined to source the leaked route.
The following is the default behavior if an incomplete configuration is entered:
- If the leak-map keyword is configured to reference a nonexistent route map, the configuration of this keyword has no effect. The summary address is advertised but all component routes are suppressed.
- If the leak-map keyword is configured but the access list does not exist or the route map does not reference the access list, the summary address and all component routes are advertised.
If you are configuring a virtual-network trunk interface and you configure the ip summary-address eigrp command, the admin-distance value of the command is not inherited by the virtual networks running on the trunk interface because the administrative distance option is not supported in the ip summary-address eigrp command on virtual network subinterfaces.
Examples
The following example shows how to configure an administrative distance of 95 on Ethernet interface 0/0 for the 192.168.0.0/16 summary address:
Router(config)# router eigrp 1 Router(config-router)# no auto-summary Router(config-router)# exit Router(config)# interface Ethernet 0/0 Router(config-if)# ip summary-address eigrp 1 192.168.0.0 255.255.0.0 95The following example shows how to configure the 10.1.1.0/24 subnet to be leaked through the 10.2.2.0 summary address:
Router(config)# router eigrp 1 Router(config-router)# exit Router(config)# access-list 1 permit 10.1.1.0 0.0.0.255 Router(config)# route-map LEAK-10-1-1 permit 10 Router(config-route-map)# match ip address 1 Router(config-route-map)# exit Router(config)# interface Serial 0/0 Router(config-if)# ip summary-address eigrp 1 10.2.2.0 255.0.0.0 leak-map LEAK-10-1-1 Router(config-if)# endThe following example configures GigabitEthernet interface 0/0/0 as a virtual network trunk interface:
Router(config)# interface gigabitethernet 0/0/0 Router(config-if)# vnet global Router(config-if-vnet)# ip summary-address eigrp 1 10.3.3.0 255.0.0.0 33ipv6 authentication key-chain eigrp
To enable authentication of Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 packets, use the ipv6 authentication key-chain eigrpcommand in interface configuration mode. To disable authentication of EIGRP for IPv6 packets, use the no form of this command.
ipv6 authentication key-chain eigrp as-number key-chain
no ipv6 authentication key-chain eigrp as-number key-chain
Usage Guidelines
EIGRP for IPv6 route authentication provides Message Digest 5 (MD5) authentication of routing updates from the EIGRP for IPv6 routing protocol. The MD5 keyed digest in each EIGRP for IPv6 packet prevents the introduction of unauthorized or false routing messages from unapproved sources.
Each key has its own key identifier, which is stored locally. The combination of the key identifier and the interface associated with the message uniquely identifies the authentication algorithm and MD5 authentication key in use.
You can configure multiple keys with lifetimes. Only one authentication packet is sent, regardless of how many valid keys exist. The software examines the key numbers in order from lowest to highest, and uses the first valid key it encounters.
Examples
The following example enables authentication for EIGRP for IPv6 for AS 1, using a key chain named chain1:
Router(config-if)# ipv6 authentication key-chain eigrp 1 chain1Related Commands
Command
Description
accept-lifetime
Sets the time period during which the authentication key on a key chain is received as valid.
ipv6 authentication mode eigrp
Specifies the type of authentication used in EIGRP for IPv6 packets.
key
Identifies an authentication key on a key chain.
key chain
Enables authentication of routing protocols.
key-string (authentication)
Specifies the authentication string for a key.
send-lifetime
Sets the time period during which an authentication key on a key chain is valid to be sent.
ipv6 bandwidth-percent eigrp
To configure the percentage of bandwidth that may be used by Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 on an interface, use the ipv6 bandwidth-percent eigrpcommand in interface configuration mode. To restore the default value, use the no form of this command.
Usage Guidelines
EIGRP for IPv6 uses as much as 50 percent of the bandwidth of a link, as defined by the bandwidth command. The ipv6 bandwidth-percent eigrp command may be used if some other fraction of the bandwidth is desired.
Note that values greater than 100 percent may be configured. The configuration option may be useful if the bandwidth is set artificially low for other reasons.
ipv6 eigrp
To enable Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 on a specified interface, use the ipv6 eigrp command in interface configuration mode. To disable EIGRP for IPv6, use the no form of this command.
Usage Guidelines
Use the ipv6 eigrp command to enable EIGRP for IPv6 on a per-interface basis.
If an autonomous system is specified, EIGRP for IPv6 is enabled only for the specified autonomous system. Otherwise, EIGRP for IPv6 is specified throughout the interface.
ipv6 hello-interval eigrp
To configure the hello interval for the Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 routing process designated by an autonomous system number, use the ipv6 hello-interval eigrp command in interface configuration mode. To restore the default value, use the no form of this command.
Command Default
For low-speed, nonbroadcast multiaccess (NBMA) networks, the default hello interval is 60 seconds. For all other networks, the default hello interval is 5 seconds.
Usage Guidelines
The default of 60 seconds applies only to low-speed, 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 EIGRP for IPv6, Frame Relay and Switched Multimegabit Data Service (SMDS) networks may 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.
ipv6 hold-time eigrp
To configure the hold time for a particular Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 routing process designated by the autonomous system number, use the ipv6 hold-time eigrpcommand in interface configuration mode. To restore the default value, use the no form of this command.
Command Default
For low-speed, nonbroadcast multiaccess (NBMA) networks, the default hold-time interval is 180 seconds. For all other networks, the default hold-time interval is 15 seconds.
Usage Guidelines
On very congested and large networks, the default hold time might not be sufficient time for all routers and access servers to receive hello packets from their neighbors. In this case, you may want to increase the hold time.
Cisco recommends 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 this 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, NBMA media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth command.
ipv6 next-hop-self eigrp
To instruct a device configured with the Enhanced Interior Gateway Routing Protocol (EIGRP) that the IPv6 next hop is the local outbound interface address, use the ipv6 next-hop-self eigrp command in interface configuration mode. To instruct EIGRP to use the received next hop instead of the local outbound interface, use the no form of this command.
Command History
Release
Modification
12.4(6)T
This command was introduced.
12.2(33)SRB
This command was integrated into Cisco IOS Release 12.2(33)SRB.
12.2(33)SXH
This command was integrated into Cisco IOS Release 12.2(33)SXH.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
15.2(1)S
This command was integrated into Cisco IOS Release 15.2(1)S. The no-ecmp-mode keyword was added.
Cisco IOS XE Release 3.5S
This command was modified. The no-ecmp-mode keyword was added.
15.2(3)T
This command was modified. The no-ecmp-mode keyword was added.
Usage Guidelines
EIGRP, by default, sets the next-hop value to the local outbound interface address for routes that it is advertising, even when advertising those routes back out of the same interface on which they were learned. To change this default, use the no ipv6 next-hop-self eigrp command to instruct EIGRP to use the received next-hop value when advertising these routes. Some exceptions to this guideline are as follows:
- If your topology does not require spoke-to-spoke dynamic tunnels, you need not configure the no ipv6 next-hop-self eigrp command.
- If your topology requires spoke-to-spoke dynamic tunnels, you must use process switching on the tunnel interface on spoke devices. Otherwise, you will need to use a different routing protocol over Dynamic Multipoint VPN (DMVPN).
The no-ecmp-mode option is an enhancement to the no ipv6 next-hop-self eigrp command. When this option is enabled, all routes to a network in the EIGRP table are evaluated to check whether routes advertised from an interface were learned on the same interface. If a route advertised by an interface was learned on the same interface, the no ipv6 next-hop-self eigrp configuration is honored and the received next hop is used to advertise this route. Disabling the IPv6 next-hop self functionality is primarily useful in DMVPN spoke-to-spoke topologies.
Examples
The following example shows how to change the default IPv6 next-hop value by disabling the ipv6 next-hop-self functionality and configuring EIGRP to use the received next-hop value to advertise routes:
Device(config)# interface serial 0 Device(config-if)# no ipv6 next-hop-self eigrp 1 no-ecmp-modeipv6 router eigrp
To place the router in router configuration mode, create an Enhanced Interior Gateway Routing Protocol (EIGRP) routing process in IPv6, and configure this process, use the ipv6router eigrpcommand in global configurationmode. To shut down a routing process, use the no form of this command.
Syntax Description
as-number
Autonomous system number.
eigrp event-log-size event-log-size
(Optional) Memory allocation value of the EIGRP event. The event-log-size value is the memory allocation, in bytes, calculated dynamically based on available memory. The event-log-size value is between 0 and the dynamically calculated number.
Command History
Release
Modification
12.4(6)T
This command was introduced.
12.2(33)SRB
The eigrp event-log-size keyword and event-log-size argument were added.
12.2(33)SXH
This command was integrated into Cisco IOS Release 12.2(33)SXH.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
Usage Guidelines
Use the ipv6 router eigrp command in global configuration mode to place the router in router configuration mode and create a routing process. Once in router configuration mode, you can configure the EIGRP for IPv6 routing process using the ipv6 router eigrp command.
ipv6 split-horizon eigrp
To enable Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 split horizon, use the ipv6split-horizon eigrpcommand in interface configuration mode. To disable split horizon, use the no form of this command.
Usage Guidelines
For networks that include links over X.25 packet-switched networks (PSNs), you can use the neighbor command in router configuration mode to disable the split horizon feature. Or, you can specify the no ipv6 split-horizon eigrp command in your configuration. However, if you do disable the split horizon feature, you must similarly disable split horizon for all routers and access servers in any relevant multicast groups on that network.
NoteIn general, we recommend that you not change the default state of split horizon unless you are certain that your application requires the change in order to advertise routes properly. 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 and access servers in any relevant multicast groups on that network.
ipv6 summary-address eigrp
To configure a summary aggregate address for a specified interface, use the ipv6summary-address eigrpcommand in interface configuration mode. To disable a configuration, use the no form of this command.
ipv6 summary-address eigrp as-number ipv6-address [admin-distance]
no ipv6 summary-address eigrp as-number ipv6-address [admin-distance]
Command Default
An administrative distance of 5 is applied to Enhanced Interior Gateway Routing Protocol (EIGRP) for IPv6 summary routes. EIGRP for IPv6 automatically summarizes to the network level, even for a single host route. No summary addresses are predefined.
Usage Guidelines
The ipv6 summary-address eigrp command is used to configure interface-level address summarization. EIGRP for IPv6 summary routes are given an administrative distance value of 5. The administrative distance metric is used to advertise a summary address without installing it in the routing table.
log-neighbor-changes (EIGRP)
To enable the logging of changes in Enhanced Interior Gateway Routing Protocol (EIGRP) neighbor adjacencies, use the log-neighbor-changescommand in IPX-router configuration mode. To disable this function, use the no form of this command.
Command History
Release
Modification
11.2
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
Usage Guidelines
Enable the logging of neighbor adjacency changes in order to monitor the stability of the routing system and to help detect problems. Log messages are of the following form:
%DUAL-5-NBRCHANGE: IPX EIGRP as-number : Neighbor address ( interface ) is state : reasonwhere the arguments have the following meanings:
as-number
Autonomous system number
address (interface)
Neighbor address
state
Up or down
reason
Reason for change
log-neighbor-changes (IPv6 EIGRP)
To enable the logging of changes in Enhanced Interior Gateway Routing Protocol (EIGRP) IPv6 neighbor adjacencies, use the log-neighbor-changes command in router configuration mode. To disable the logging of changes in EIGRP IPv6 neighbor adjacencies, use the no form of this command.
Usage Guidelines
The log-neighbor-changes command enables the logging of neighbor adjacency changes to monitor the stability of the routing system and to help detect problems.
Logging is enabled by default. To disable the logging of neighbor adjacency changes, use the no form of this command.
log-neighbor-warnings
NoteEffective with Cisco IOS Release 15.0(1)M, 12.2(33)SRE and Cisco IOS XE Release 2.5, the log-neighbor-warnings command was replaced by the eigrp log-neighbor-warnings command for IPv4 and IPv6 configurations. The log-neighbor-warnings command is still available for IPX configurations.
To enable the logging of Enhanced Interior Gateway Routing Protocol (EIGRP) neighbor warning messages, use the log-neighbor-warnings command in router configuration mode. To disable the logging of EIGRP neighbor warning messages, use the no form of this command.
Syntax Description
seconds
(Optional) The time interval (in seconds) between repeated neighbor warning messages. The range of seconds is from 1 through 65535.
Command History
Release
Modification
12.4(6)T
This command was introduced.
12.2(33)SRB
This command was integrated into Cisco IOS Release 12.2(33)SRB.
12.2(33)SXH
This command was integrated into Cisco IOS Release 12.2(33)SXH.
Cisco IOS XE Release 2.1
This command was introduced on Cisco ASR 1000 Series Routers.
15.0(1)M
This command was replaced by the eigrp log-neighbor-warnings command for IPv4 and IPv6 configurations. The log-neighbor-warnings command is still available for IPX configurations.
12.2(33)SRE
This command was replaced by the eigrp log-neighbor-warnings command for IPv4 and IPv6 configurations. The log-neighbor-warnings command is still available for IPX configurations.
Cisco IOS XE Release 2.5
This command was replaced by the eigrp log-neighbor-warnings command for IPv4 and IPv6 configurations. The log-neighbor-warnings command is still available for IPX configurations.
Usage Guidelines
When neighbor warning messages occur, they are logged by default. With the log-neighbor-warnings command, you can disable and enable the logging of neighbor warning messages and configure the interval between repeated neighbor warning messages.
match extcommunity
To match Border Gateway Protocol (BGP) or Enhanced Interior Gateway Routing Protocol (EIGRP) extended community list attributes, use the match extcommunity command in route-map configuration mode. To remove the match extcommunitycommand from the configuration file and remove the BGP or EIGRP extended community list attribute entry, use the no form of this command.
Command History
Release
Modification
12.1
This command was introduced.
12.0(22)S
The maximum number of expanded extended community list numbers was changed from 199 to 500 in Cisco IOS Release 12.0(22)S.
12.2(15)T
The maximum number of expanded extended community list numbers was changed from 199 to 500 in Cisco IOS Release 12.2(15)T.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.0(1)M
This command was modified. Support for EIGRP was added.
12.2(33)SRE
This command was modified. Support for EIGRP was added.
Cisco IOS XE Release 2.5
This command was modified. Support for EIGRP was added.
12.2(33)XNE
This command was modified. Support for EIGRP was added.
Usage Guidelines
Extended community attributes are used to configure, filter, and identify routes for virtual routing and forwarding instances (VRFs) and Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs).
The match extcommunity command is used to configure match clauses that use extended community attributes in route maps. All of the standard rules of match and set clauses apply to the configuration of extended community attributes.
Examples
The following example shows that the routes that match extended community list 500 will have the weight set to 100. Any route that has extended community 1 will have the weight set to 100.
Router(config)# ip extcommunity-list 500 rt 100:2 Router(config-extcomm-list)# exit Router(config)# route-map MAP_NAME permit 10 Router(config-route-map)# match extcommunity 1 Router(config-route-map)# set weight 100Related Commands
Command
Description
ip extcommunity-list
Creates an extended community list for BGP and controls access to it.
route-map (IP)
Defines the conditions for redistributing routes from one routing protocol into another.
set extcommunity
Sets BGP extended community attributes.
set weight
Specifies the BGP weight for the routing table.
show ip extcommunity-list
Displays routes that are permitted by the extended community list.
show route-map
Displays configured route maps.
match tag list
To filter routes that match a specified route tag list, use the match tag list command in route-map configuration mode. To remove the route tag list entry, use the no form of this command.
Usage Guidelines
The ellipsis (...) in the command syntax indicates that the command input can include multiple values for the list-name argument. Route tag lists are used to filter routes. A single list can have multiple criteria for routes. Only routes that match all criteria specified in the route tag list are filtered.
maximum-prefix
To limit the number of prefixes that are accepted under an address family by an Enhanced Interior Gateway Routing Protocol (EIGRP) process, use the maximum-prefix command in address family configuration mode or address family topology configuration mode. To disable this function, use the no form of this command.
maximum-prefix maximum { [ [threshold] [dampened] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] ] | [warning-only] }
no maximum-prefix
Syntax Description
maximum
Maximum number of prefixes allowed under an address family. The range for this argument is a number from 1 to 4294967295.
Note The number of prefixes that can be configured is limited only by the available system resources on the router.
threshold
(Optional) The prefix percentage number. Valid values are 1 to 100. The default is 75. This value causes the router to generate syslog warning messages when the specified percentage of the maximum-prefix limit has been exceeded.
dampened
(Optional) Configures a decay penalty to be applied to the restart-time period each time the maximum-prefix limit is exceeded. The half-life for the decay penalty is 150 percent of the default or user-defined restart-time value in minutes. This keyword is disabled by default.
reset-time minutes
(Optional) Configures the router to reset the restart count to 0 after the default or user-defined reset-time period has expired. The range of values that can be applied with the minutes argument is from 1 to 65535 minutes. The default reset-time period is 15 minutes.
restart minutes
(Optional) Configures a time period in which the router will not form adjacencies or accept redistributed routes from the Routing Information Base (RIB) after the maximum-prefix limit has been exceeded. The value for the minutes argument is from 1 to 65535 minutes. The default restart-time period is 5 minutes.
restart-count number
(Optional) Configures the number of times a peering session can be automatically reestablished after the peering session has been torn down or after a redistribute route has been cleared and relearned because the maximum-prefix limit has been exceeded. The default restart-count limit is 3.
Caution Once the restart count threshold has been crossed, you will need to enter the clear ip route * or clear ip eigrp neighbor command to reestablish normal peering and/or redistribution.
warning-only
(Optional) Configures the router to generate syslog messages only when the maximum-prefix limitis reached, instead of suspending peering session or route redistribution. This keyword is disabled by default.
Command Default
The number of prefixes that are accepted under an address family by an EIGRP process is not limited.
Command Modes
Address family configuration (config-router-af) Address family topology configuration (config-router-af-topology)
Command History
Release
Modification
12.0(29)S
This command was introduced.
12.3(14)T
This command was integrated into Cisco IOS Release 12.3(14)T.
15.0(1)M
This command was modified. Address family topology configuration mode was added for EIGRP named configurations.
12.2(33)SRE
This command was integrated into Cisco IOS Release 12.2(33)SRE.
Cisco IOS XE Release 2.6
This command was integrated into Cisco IOS XE Release 2.6.
Usage Guidelines
The maximum-prefix command is used to configure an EIGRP process to limit the number prefixes that are accepted from all sources. When the maximum-prefix limit is exceeded, sessions with remote peers are torn down, all routes learned from remote peers and through redistribution are removed from the topology and routing tables, and redistribution and peering is suspended for the default or user-defined time period.
Inherited Timer Values
Default or user-defined restart, restart-count, and reset-time values for the process-level configuration of this feature, configured with the maximum-prefix command, are inherited by the redistribute maximum-prefix and neighbor maximum-prefix command configurations by default. If a single peer is configured with the neighbor maximum-prefix command, a process-level configuration or a configuration that is applied to all neighbors will be inherited.
Examples
The following example, starting in global configuration mode, configures the maximum prefix limit for an EIGRP process, which includes routes learned through redistribution and routes learned through EIGRP peering sessions. The maximum limit is set to 50000 prefixes. When the number of prefixes learned through redistribution reaches 37,500 (75 percent of 50,000), warning messages will be displayed in the console. When the maximum prefix limit is exceeded, all peering sessions will be reset, the topology and routing tables will be cleared and redistributed routes and all peering sessions will be placed in a penalty state.
Router(config)# router eigrp 100 Router(config-router)# address-family ipv4 vrf VRF1 Router(config-router-af)# maximum-prefix 50000 Router(config-router-af)# endThe following example configures the maximum prefix limit for an EIGRP named configuration process:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# topology base Router(config-router-af-topology)# maximum-prefix 50000Related Commands
Command
Description
clear ip eigrp neighbors
Deletes entries from the EIGRP neighbor table.
clear ip eigrp vrf neighbor
Deletes neighbor entries from the VRF table.
clear ip route
Deletes routes from the IP routing table.
neighbor maximum-prefix
Limits the number of prefixes that are accepted from a single EIGRP neighbor or from all EIGRP neighbors.
redistribute maximum-prefix
Limits the number of prefixes redistributed into an EIGRP process.
metric holddown
To keep new Enhanced Interior Gateway Routing Protocol (EIGRP) routing information from being used for a certain period of time, use the metric holddown command in router configuration mode. To disable this feature, use the no form of this command.
Command History
Release
Modification
10.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Usage Guidelines
The holddown state keeps new routing information from being used for a certain period of time. This function can prevent routing loops caused by slow convergence. It is sometimes advantageous to disable the holddown state to increase the ability of the network to quickly respond to topology changes; this command provides this function.
Use the metric holddown command if other routers or access servers within the EIGRP autonomous system are not configured with the no metric holddown command. If all routers are not configured the same way, you increase the possibility of routing loops.
metric maximum-hops
To have the IP routing software advertise as unreachable routes with a hop count higher than is specified by the command (Enhanced Interior Gateway Routing Protocol [EIGRP] only), use the metric maximum-hops command in router configuration mode or address family topology configuration mode. Toreset the value to the default, use the no form of this command.
Syntax Description
hops-number
Maximum hop count (in decimal). The default value is 100; the maximum number of hops that can be specified is 255.
Command Modes
Router configuration (config-router) Address family topology configuration (config-router-af-topology)
Command History
Release
Modification
10.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
15.0(1)M
This command was modified. The address-family topology configuration mode was added.
12.2(33)SRE
This command was modified. The address-family topology configuration mode was added.
Cisco IOS XE Release 2.5
This command was modified. The address-family topology configuration mode was added.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
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-number argument.
Examples
In the following example, a router in autonomous system 71 attached to network 10.0.0.0 wants a maximum hop count of 200, doubling the default. The network administrators configured the router hop count to 200 because they have a complex WAN that can generate a large hop count under normal (nonlooping) operations.
Router(config)# router eigrp 71 Router(config-router)# network 172.16.0.0 Router(config-router)# metric maximum-hops 200The following example shows how to configure EIGRP autonomous-system 4453 to have a maximum hop count of 200:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# topology base Router(config-router-af-topology)# metric maximum-hops 200Related Commands
Command
Description
address-family (EIGRP)
Enters address-family configuration mode to configure an EIGRP routing instance.
metric holddown
Keeps new EIGRP routing information from being used for a certain period of time.
metric weights (EIGRP)
Allows the tuning of the EIGRP metric calculations.
network (EIGRP)
Specifies the network for an EIGRP routing process.
router eigrp
Configures the EIGRP address-family process.
topology (EIGRP)
Configures an EIGRP process to route IP traffic under the specified topology instance and enters address-family topology configuration mode.
metric rib-scale
To set the Routing Information Base (RIB) scaling factor for the Enhanced Interior Gateway Routing Protocol (EIGRP), use the metric rib-scale command in address family configuration mode. To remove the metric value and restore the default state, use the no form of this command.
Usage Guidelines
Use the metric rib-scale command to clear all EIGRP routes and replace them with new metric values in the RIB.
metric weights (EIGRP)
To tune the Enhanced Interior Gateway Routing Protocol (EIGRP) metric calculations, use the metric weights command in router configuration mode or address family configuration mode. To reset the values to their defaults, use the no form of this command.
Router Configuration
metric weights tos k1 k2 k3 k4 k5
no metric weights
Address Family Configuration
metric weights tos [ k1 [ k2 [ k3 [ k4 [ k5 [k6] ] ] ] ] ]
no metric weights
Syntax Description
Command History
Release
Modification
10.0
This command was introduced.
12.4(6)T
This command was modified. Support for IPv6 was added.
12.2(33)SRB
This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
12.2(33)SRE
This command was modified. The address family configuration mode was added.
15.0(1)M
This command was modified. The address family configuration mode was added.
Cisco IOS XE Release 2.5
This command was modified. The address family configuration mode was added.
15.1(3)S
This command was modified. The k6 argument was added.
Cisco IOS XE Release 3.4S
This command was modified. The k6 argument was added.
15.2(2)T
This command was modified. The k6 argument was added.
15.1(1)SY
This command was modified. The k6 argument was added.
Usage Guidelines
Use this command to alter the default behavior of EIGRP routing and metric computation and to allow the tuning of the EIGRP metric calculation for a particular type of service (ToS).
If k5 equals 0, the composite EIGRP metric is computed according to the following formula:
metric = [k1 * bandwidth + (k2 * bandwidth)/(256 – load) + k3 * delay + K6 * extended metrics]
If k5 does not equal zero, an additional operation is performed:
metric = metric * [k5/(reliability + k4)]
Scaled Bandwidth= 107/minimum interface bandwidth (in kilobits per second) * 256
Delay is in tens of microseconds for classic mode and pico seconds for named mode. In classic mode, a delay of hexadecimal FFFFFFFF (decimal 4294967295) indicates that the network is unreachable. In named mode, a delay of hexadecimal FFFFFFFFFFFF (decimal 281474976710655) indicates that the network is unreachable.
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.
Examples
The following example shows how to set the metric weights to slightly different values than the defaults:
Router(config)# router eigrp 109 Router(config-router)# network 192.168.0.0 Router(config-router)# metric weights 0 2 0 2 0 0The following example shows how to configure an address-family metric weight to ToS: 0; K1: 2; K2: 0; K3: 2; K4: 0; K5: 0; K6:1:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4533 Router(config-router-af)# metric weights 0 2 0 2 0 0 1Related Commands
Command
Description
address-family (EIGRP)
Enters address family configuration mode to configure an EIGRP routing instance.
bandwidth (interface)
Sets a bandwidth value for an interface.
delay (interface)
Sets a delay value for an interface.
ipv6 router eigrp
Configures an IPv6 EIGRP routing process.
metric holddown
Keeps new EIGRP routing information from being used for a certain period of time.
metric maximum-hops
Causes IP routing software to advertise routes with a hop count higher than what is specified by the command (EIGRP only) as unreachable routes.
router eigrp
Configures an EIGRP routing process.
neighbor (EIGRP)
To define a neighboring device with which an Enhanced Interior Gateway Routing Protocol (EIGRP) device can exchange routing information, use the neighbor command in router configuration mode or address family configuration mode. To remove an entry, use the no form of this command.
neighbor { ip-address | ipv6-address } interface-type interface-number [ remote maximum-hops [ lisp-encap [ lisp-id ] ] ]
no neighbor { ip-address | ipv6-address } interface-type interface-number
Syntax Description
ip-address
IP address of a peer router with which routing information will be exchanged.
ipv6-address
IPv6 address of a peer router with which routing information will be exchanged.
interface-type
Interface or subinterface through which peering sessions are established.
interface-number
Number of the interface or subinterface.
remote
(Optional) Specifies that the neighbor is remote.
maximum-hops
(Optional) Maximum hop count. Valid range is from 2 to 100. This argument is available only when the remote keyword is configured.
lisp-encap (Optional) Specifies that any data to routes from this remote neighbor is Location/ID Separation Protocol (LISP) encapsulated. lisp-top-id
(Optional) Identity of the LISP instance. Only one LISP ID is allowed per device. Command History
Release
Modification
10.0
This command was introduced.
12.4(6)T
This command was modified. The ipv6-address argument was added.
12.2(33)SRB
This command was integrated into Cisco IOS Release 12.2(33)SRB.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.0(1)M
This command was modified. Address family configuration mode was added
12.2(33)SRE
This command was modified. Address family configuration mode was added.
Cisco IOS XE Release 2.5
This command was modified. Address family configuration mode was added.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 3.10
This command was modified. The lisp-encap keyword an lisp-id argument were added.
15.3(3)S
This command was integrated into Cisco IOS Release 15.3(3)S.
Usage Guidelines
Multiple neighbor statements can be used to establish peering sessions with specific EIGRP neighbors. The interface through which EIGRP exchanges routing updates must be specified in the neighbor statement. The interfaces through which two EIGRP neighbors exchange routing updates must be configured with IP addresses from the same network.
NoteConfiguring the passive-interface command suppresses all incoming and outgoing routing updates and hello messages. EIGRP neighbor adjacencies cannot be established or maintained over an interface that is configured as passive.
Examples
The following example shows how to configure EIGRP peering sessions with neighbors 192.168.1.1 and 192.168.2.2:
Router(config)# router eigrp 1 Router(config-router)# network 192.168.0.0 Router(config-router)# neighbor 192.168.1.1 Ethernet 0/0 Router(config-router)# neighbor 192.168.2.2 Ethernet 1/1The following named configuration example shows how to configure EIGRP to send address-family updates to specific neighbors:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# neighbor 192.168.1.1 ethernet 0/0 Router(config-router-af)# neighbor 10.1.1.2 loopback 0 remote 10The following example shows how to enable EIGRP to identify and reach EIGRP Route Reflectors in a network. An EIGRP Route Reflector is an EIGRP peer that forms adjacencies with customer edge routers in a network and exchange routes between them without changing the next hop or metrics of these routes.
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# neighbor 192.168.1.1 gigabitethernet 0/0/1 remote 2 lisp-encap 1Related Commands
Command
Description
address-family (EIGRP)
Enters address family configuration mode to configure an EIGRP routing instance.
ipv6 router eigrp
Creates and configures an EIGRP routing process in IPv6 configurations.
passive-interface
Disables sending routing updates on an interface.
router eigrp
Configures an EIGRP routing process.
network (EIGRP) Specifies the network for an EIGRP routing process.
neighbor description
To associate a description with a neighbor, use the neighbor description command in router configuration mode or address family configuration mode. To remove the description, use the no form of this command.
neighbor { ip-address | peer-group-name } description text
no neighbor { ip-address | peer-group-name } description [text]
Syntax Description
ip-address
IP address of the neighbor.
peer-group-name
Name of an EIGRP peer group. This argument is not available in address-family configuration mode.
text
Text (up to 80 characters in length) that describes the neighbor.
Command History
Release
Modification
11.3
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.0(1)M
This command was modified. Address-family configuration mode was added.
12.2(33)SRE
This command was integrated into Cisco IOS Release 12.2(33)SRE.
Cisco IOS XE Release 2.6
This command was integrated into Cisco IOS XE Release 2.6.
Examples
In the following examples, the description of the neighbor is “peer with example.com”:
Router(config)# router bgp 109 Router(config-router)# network 172.16.0.0 Router(config-router)# neighbor 172.16.2.3 description peer with example.comIn the following example, the description of the address family neighbor is “address-family-peer”:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# network 172.16.0.0 Router(config-router-af)# neighbor 172.16.2.3 description address-family-peerneighbor maximum-prefix (EIGRP)
To limit the number of prefixes that are accepted from a single Enhanced Interior Gateway Protocol (EIGRP) neighbor or from all EIGRP neighbors, use the neighbor maximum-prefix command in address family configuration mode. To disable this function, use the no form of this command.
Single Neighbor Configuration
neighbor ip-address maximum-prefix maximum [ threshold ] [warning-only]
no neighbor ip-address maximum-prefix
All Neighbor Configuration
neighbor maximum-prefix maximum [ threshold ] [ { [dampened] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] | warning-only } ]
no neighbor maximum-prefix
Syntax Description
ip-address
IP address of a single peer.
maximum
Maximum number of prefixes accepted. The range for this argument is a number from 1 to 4294967295.
Note The number of prefixes that can be configured is limited only by the available system resources on the router.
threshold
(Optional) Configures the router to generate syslog warning messages when the specified percentage of the maximum-prefix limit has been reached. The prefix percentage number that can be configured for the threshold argument is from 1 to 100. The default is 75 percent.
warning-only
(Optional) Configures the router to generate syslog messages only when the maximum-prefix limitis reached, instead of terminating the peering session. This keyword is disabled by default.
dampened
(Optional) Configures a decay penalty to be applied to the restart-time period each time the maximum-prefix limit is reached. The half-life for the decay penalty is 150 percent of the default or user-defined restart-time value in minutes. This keyword is disabled by default.
reset-time minutes
(Optional) Configures the router to reset the restart count to 0 after the default or configured reset-time period has expired. The value for the minutes argument is from 1 to 65535 minutes. The default reset-time period is 15 minutes.
restart minutes
(Optional) Configures a time period in which the router will not form adjacencies or accept redistributed routes from the RIB after the maximum-prefix limit has been reached. The value for the minutes argument is from 1 to 65535 minutes. The default restart-time period is 5 minutes.
restart-count number
(Optional) Configures the number of times a peering session can be automatically reestablished after the peering session has been torn down or after a redistribute route has been cleared and relearned because the maximum-prefix limit has been reached. The default restart-count limit is 3.
Caution Once the restart count threshold has been crossed, you will need to enter the clear ip route * or clear ip eigrp neighbor command to reestablish normal peering and/or redistribution.
Command Default
The number of prefixes that can be configured is limited only by the available system resources on the router.
Usage Guidelines
The neighbor maximum-prefix command can be configured to protect an individual peering session or to protect all peering sessions. When this feature is enabled and the maximum-prefix limit has been reached, the router will tear down the peering session, clear all routes that were learned from the peer, and then place the peer in a penalty state for the default or user-defined time period. After the penalty time period expires, normal peering will be reestablished.
NoteIn EIGRP, neighbor commands have been traditionally used to configure static neighbors. In the context of the EIGRP Prefix Limiting feature, however, the neighbor maximum-prefix command can be used to configure the maximum-prefix limit for both statically configured neighbors and dynamically discovered neighbors.
When you configure the neighbor maximum-prefix command to protect a single peering session, only the maximum-prefix limit, the percentage threshold, and the warning-only configuration options can be configured. Session dampening, restart, and reset timers are configured on a global basis.
Inherited Timer Values
Default or user-defined restart, restart-count, and reset-time values for the process-level configuration of this feature, configured with the maximum-prefix command, are inherited by the redistribute maximum-prefix and neighbor maximum-prefix command configurations by default. If a single peer is configured with the neighbor maximum-prefix command, a process-level configuration or a configuration that is applied to all neighbors will be inherited.
Examples
The following example, starting in global configuration mode, configures the maximum prefix limit for a single peer. The maximum limit is set to 1000 prefixes, and the warning threshold is set to 80 percent. When the maximum prefix limit is reached for the configured neighbor, adjacency with this neighbor will be brought down and all routes learned from it will be cleared. The neighbor will be placed in a penalty state for 4 minutes (user-defined penalty value). This function will not affect the relationship with any other neighbor.
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# neighbor 10.0.0.1 maximum-prefix 1000 80 Router(config-router-af)# endExamples
The following example, starting in global configuration mode, configures the maximum prefix limit for all peers. The maximum limit is set to 10,000 prefixes, the warning threshold is set to 90 percent, the restart timer is set to 4 minutes, a decay penalty is configured for the restart timer with the dampened keyword, and all timers are configured to be reset to 0 every 60 minutes. When the maximum prefix limit is reached for any neighbor, adjacency with this neighbor will be brought down and all routes learned from it will be cleared. This function will not affect the relationship with any other neighbor. The offending peer will be placed in a penalty state for 4 minutes (user-defined penalty value). A dampening exponential decay penalty will also be applied.
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 virtual-name autonomous-system 4453 Router(config-router-af)# neighbor maximum-prefix 10000 90 dampened reset-time 60 restart 4 Router(config-router-af)# endRelated Commands
Command
Description
address-family (EIGRP)
Enters address family configuration mode to configure an EIGRP routing instance.
clear ip eigrp neighbors
Deletes entries from the EIGRP neighbor table.
clear ip eigrp vrf neighbor
Deletes neighbor entries from the VRF table.
clear ip route
Deletes routes from the IP routing table.
neighbor maximum-prefix
Limits the number of prefixes that are accepted from a single EIGRP neighbor or from all EIGRP neighbors.
redistribute maximum-prefix (EIGRP)
Limits the number of prefixes redistributed into an EIGRP process.
network (EIGRP)
To specify the network for an Enhanced Interior Gateway Routing Protocol (EIGRP) routing process, use the network command in router configuration mode or address-family configuration mode. To remove an entry, use the no form of this command.
Command History
Release
Modification
10.0
This command was introduced.
12.0(4)T
The network-mask argument was added.
12.0(22)S
Address-family support for EIGRP was added.
12.2(15)T
Address-family support for EIGRP was added.
12.2(18)S
Address-family support for EIGRP was added.
12.2(27)SBC
This command was integrated into Cisco IOS Release 12.2(27)SBC.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Usage Guidelines
When the network command is configured for an EIGRP routing process, the router matches one or more local interfaces. The network command matches only local interfaces that are configured with addresses that are within the same subnet as the address that has been configured with the networkcommand. The router then establishes neighbors through the matched interfaces. There is no limit to the number of network statements (network commands) that can be configured on a router.
Use a wildcard mask as a shortcut to group networks together. A wildcard mask matches everything in the network part of an IP address with a zero. Wildcard masks target a specific host/IP address, entire network, subnet, or even a range of IP addresses.
When entered in address-family configuration mode, this command applies only to named EIGRP IPv4 configurations. Named IPv6 and Service Advertisement Framework (SAF) configurations do not support this command in address-family configuration mode.
Examples
The following example configures EIGRP autonomous system 1 and establishes neighbors through network 172.16.0.0 and 192.168.0.0:
Router(config)# router eigrp 1 Router(config-router)# network 172.16.0.0 Router(config-router)# network 192.168.0.0 Router(config-router)# network 192.168.0.0 255.255.255.0The following example configures EIGRP address-family autonomous system 4453 and establishes neighbors through network 172.16.0.0 and 192.168.0.0:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# network 172.16.0.0 Router(config-router-af)# network 192.168.0.0next-hop-self
To enable the Enhanced Interior Gateway Routing Protocol (EIGRP) to advertise routes with the local outbound interface address as the next hop, use the next-hop-self command in address family interface configuration mode. To instruct an EIGRP device to use the received next hop instead of the local outbound interface address, use the no form of this command.
Command Default
The next-hop-self state is enabled by default, which allows EIGRP to use a local address in the next-hop field of its routing advertisements.
Command History
Release
Modification
15.0(1)M
This command was introduced.
12.2(33)SRE
This command was integrated into Cisco IOS Release 12.2(33)SRE.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 2.5
This command was integrated into Cisco IOS XE Release 2.5.
Cisco IOS XE Release 3.5S
This command was modified. The no-ecmp-mode keyword was added.
15.2(1)S
This command was integrated into Cisco IOS Release 15.2(1)S. The no-ecmp-mode keyword was added.
15.2(3)T
This command was modified. The no-ecmp-mode keyword was added.
Usage Guidelines
The next-hop-self command is an interface-based command. EIGRP, by default, sets the next-hop value to the local outbound interface address for routes that it is advertising, even when advertising those routes back out of the same interface on which they were learned. To change this default, you must use the no next-hop-self command to instruct EIGRP to use the received next-hop value when advertising these routes.
The no-ecmp-mode option is an enhancement to the no next-hop-self command. When this option is enabled, all paths to a network in the EIGRP table are evaluated to check whether routes advertised from an interface were learned on the same interface. If the route advertised by an interface was learned on the same interface, the no next-hop-self configuration is honored and the received next hop is used to advertise this route. Disabling the next-hop self functionality is primarily useful in Dynamic Multipoint VPN (DMVPN) spoke-to-spoke topologies.
Before configuring the no next-hop-self command, you must disable the split-horizon functionality. Split horizon is a protocol-independent parameter that blocks route information from being advertised by a device out of any interface from which that information originated. Use the no split-horizon command to disable split horizon.
Examples
The following example shows how to change the default next-hop value in IPv4 address family interface configurations by disabling the next-hop self functionality and configuring EIGRP to use the received next-hop value to advertise routes:
Device(config)# router eigrp virtual-name Device(config-router)# address-family ipv4 autonomous-system 33 Device(config-router-af)# af-interface ethernet0/0 Device(config-router-af-interface)# no next-hop-self no-ecmp-modeThe following example shows how to change the default next-hop value in IPv6 address family interface configurations:
Device(config)# router eigrp virtual-name Device(config-router)# address-family ipv6 autonomous-system 33 Device(config-router-af)# af-interface ethernet0/0 Device(config-router-af-interface)# no next-hop-self no-ecmp-modensf (EIGRP)
To enable Cisco nonstop forwarding (NSF) operations for the Enhanced Interior Gateway Routing Protocol (EIGRP), use the nsf command in router configuration or address family configuration mode. To disable EIGRP NSF and to remove the EIGRP NSF configuration from the running-configuration file, use the no form of this command.
Command History
Release
Modification
12.2(18)S
This command was introduced.
12.2(28)SB
This command was integrated into Cisco IOS Release 12.2(28)SB.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXH
This command was integrated into Cisco IOS Release 12.2(33)SXH.
15.0(1)M
This command was modified. Support for Address family configuration mode was added.
12.2(33)SRE
This command was modified. Support for Address family configuration mode was added.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 2.5
This command was integrated into Cisco IOS XE Release 2.5.
Cisco IOS XE Release 3.6S
This command was modified. Support for IPv6 and IPv6 VPN Routing and Forwarding (VRF) was added.
15.2(2)S
This command was modified. Support for IPv6 and IPv6 VRF was added.
Usage Guidelines
The nsf command is used to enable or disable EIGRP NSF support on an NSF-capable router. NSF is supported only on platforms that support High Availability.
Examples
The following example shows how to disable NSF:
Device# configure terminal Device(config)# router eigrp 101 Device(config-router)# no nsf Device(config-router)# endThe following example shows how to enable EIGRP IPv6 NSF:
Device# configure terminal Device(config)# router eigrp virtual-name-1 Device(config-router)# address-family ipv6 autonomous-system 10 Device(config-router-af)# nsf Device(config-router-af)# endRelated Commands
Command
Description
debug eigrp address-family ipv6 notifications
Displays information about EIGRP address family IPv6 event notifications.
debug eigrp nsf
Displays notifications and information about NSF events for an EIGRP routing process.
debug ip eigrp notifications
Displays information and notifications for an EIGRP routing process.
show ip protocols
Displays the parameters and the current state of the active routing protocol process.
show ipv6 protocols
Displays the parameters and the current state of the active IPv6 routing protocol process.
timers graceful-restart purge-time
Sets the graceful-restart purge-time timer to determine how long an NSF-aware router that is running EIGRP must hold routes for an inactive peer.
timers nsf converge
Sets the maximum time that the restarting router must wait for the end-of-table notification from an NSF-capable or NSF-aware peer.
timers nsf signal
Sets the maximum time for the initial restart period.
offset-list (EIGRP)
To add an offset to incoming and outgoing metrics to routes learned via Enhanced Interior Gateway Routing Protocol (EIGRP), use the offset-list command in router configuration mode or address family topology configuration mode. To remove an offset list, use the no form of this command.
offset-list { access-list-number | access-list-name } { in | out } offset [ interface-type interface-number ]
no offset-list { access-list-number | access-list-name } { in | out } offset [ interface-type interface-number ]
Syntax Description
access-list-number | access-list-name
Standard access list number or name to be applied. Access list number 0 indicates all networks (networks, prefixes, or routes). If the offset value is 0, no action is taken.
in
Applies the access list to incoming metrics.
out
Applies the access list to outgoing metrics.
offset
Positive offset to be applied to metrics for networks matching the access list. If the offset is 0, no action is taken.
interface-type
(Optional) Interface type to which the offset list is applied.
interface-number
(Optional) Interface number to which the offset list is applied.
Command Default
No offset values are added to incoming or outgoing metrics to routes learned via EIGRP.
Command Modes
Router configuration (config-router) Address family topology configuration (config-router-af-topology)
Command History
Release
Modification
10.0
This command was introduced.
10.3
The interface-type and interface-number arguments were added.
11.2
The access-list-name argument was added.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.0(1)M
This command was modified. The address family configuration mode was added.
12.2(33)SRE
This command was modified. The address family configuration mode was added.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 2.5
This command was modified. The address family configuration mode was added.
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 offset of the extended offset list is added to the metric.
Examples
In the following example, the router applies an offset of 10 to the delay component of the router only to access list 21:
Router(config-router)# offset-list 21 out 10In the following example, the router applies an offset of 10 to routes learned from Ethernet interface 0:
Router(config-router)# offset-list 21 in 10 ethernet 0In the following example, the router applies an offset of 10 to routes learned from Ethernet interface 0 in an EIGRP named configuration:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 1 Router(config-router-af)# topology base Router(config-router-af-topology)# offset-list 21 in 10 ethernet0passive-interface (EIGRP)
To suppress Enhanced Interior Gateway Routing Protocol (EIGRP) hello packets and routing updates on interfaces while still including the interface addresses in the topology database, use the passive-interface command in router configuration mode, address-family configuration mode, or address-family interface configuration mode. To reenable outgoing hello packets and routing updates, use the no form of this command.
passive-interface [default] [ interface-type interface-number ]
no passive-interface [default] [ interface-type interface-number ]
Syntax Description
default
(Optional) Configures all interfaces as passive.
interface-type
(Optional) Interface type. For more information, use the question mark (?) online help function.
interface-number
(Optional) Interface or subinterface number. For more information about the numbering syntax for your networking device, use the question mark (?) online help function.
Command Modes
Router configuration (config-router) Address-family configuration (config-router-af) Address-family interface configuration (config-router-af-interface)
Command History
Release
Modification
15.0(1)M
This command was introduced.
12.2(33)SRE
This command was integrated into Cisco IOS Release 12.2(33)SRE.
12.2(33)XNE
This command was integrated into Cisco IOS Release 12.2(33)XNE.
Cisco IOS XE Release 2.5
This command was integrated into Cisco IOS XE Release 2.5.
15.3(2)S
This command was implemented on the Cisco ASR 901 Series Aggregation Services Routers.
Usage Guidelines
Use the passive-interface(EIGRP) command to select interfaces that will not form EIGRP neighbor adjacencies yet include the interface addresses in the EIGRP topology database. When the passive-interface (EIGRP) command is configured, networks defined on the interface are added to the EIGRP topology database while routing updates and hello packets over the passive interfaces are suppressed.
The default keyword sets all interfaces to passive. Individual interfaces can be specified to override the default passive-interface state by using the no passive-interfacecommand. The default keyword is useful when there are more passive interfaces than active interfaces. If the default keyword is not specified, the interfaces are considered nonpassive.
Examples
The following example shows how to place the router in the router configuration mode and set all EIGRP interfaces to the passive state and then set Ethernet interface 0/0 to a nonpassive state:
Router(config)# router eigrp 109 Router(config-router)# passive-interface default Router(config-router)# no passive-interface ethernet0/0The following example shows how to place the router in the address-family configuration mode and set all EIGRP interfaces in VRF RED to the passive state and then set Ethernet interface 0/0 to a nonpassive state:
Router(config)# router eigrp 109 Router(config-router)# address-family ipv4 vrf RED Router(config-router-af)# passive-interface default Router(config-router-af)# no passive-interface ethernet0/0The following EIGRP named address-family interface configuration example sets all interfaces in an address family to passive and then sets Ethernet 0/0 to a nonpassive state:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 autonomous-system 4453 Router(config-router-af)# af-interface default Router(config-router-af-interface)# passive-interface Router(config-router-af-interface)# exit Router(config-router-af)# af-interface ethernet0/0 Router(config-router-af-interface)# no passive-interfaceRelated Commands
Command
Description
address-family (EIGRP)
Enters address-family configuration mode to configure an EIGRP routing instance.
af-interface
Enters address-family interface configuration mode to configure interface-specific EIGRP commands.
network (EIGRP)
Specifies the network for an EIGRP routing process.
router eigrp
Configures the EIGRP address-family process.
redistribute eigrp
To redistribute IPv4 routes from Enhanced Interior Gateway Routing Protocol (EIGRP), use the redistribute eigrp command in router configuration mode. To disable the configuration, use the no form of this command.
redistribute eigrp system-number [ metric bandwidth-metric delay-metric reliability-metric effective-bandwidth-metric mtu-bytes ] [ route-map pointer-name ]
no redistribute eigrp system-number [ metric bandwidth-metric delay-metric reliability-metric effective-bandwidth-metric mtu-bytes ] [ route-map pointer-name ]
Syntax Description
system-number
Autonomous system number. The range is from 1 to 65535.
metric
(Optional) Specifies the metric for redistributed routes.
bandwidth-metric
(Optional) Maximum bandwidth of the route, in kilobits per second (kb/s). The range is from 1 to 4294967295.
delay-metric
(Optional) EIGRP route delay metric, in microseconds. The range is from 1 to 4294967295.
reliability-metric
(Optional) EIGRP reliability metric. The range is from 0 to 255.
effective-bandwidth- metric
(Optional) Effective bandwidth of the route. The range is from 1 to 255.
mtu-bytes
(Optional) The smallest allowed value for the maximum transmission unit (MTU), in bytes. The range is from 1 to 65535.
route-map
(Optional) Specifies the route map reference.
pointer-name
(Optional) Pointer to route-map entries.
Command History
Release
Modification
12.2(8)T
This command was introduced in a release earlier than Cisco IOS Release 12.2(8)T.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(33)SXI
This command was integrated into Cisco IOS Release 12.2(33)SXI.
Cisco IOS XE Release 2.1
This command was implemented on the Cisco ASR 1000 Series Aggregation Services Routers.
Usage Guidelines
Use the redistribute eigrp command to redistribute the routes learned through the EIGRP routing instances to other routing protocols. Forward redistribution of the EIGRP routes is allowed before creating the EIGRP routing instance. The EIGRP redistribution takes place as soon as the routing instance is created.
The metric value specified in the redistributecommand supersedes the metric value specified using the default-metriccommand.
NoteIn Cisco IOS Release 12.0(33)S, the redistribution eigrpcommand is not allowed if the EIGRP router is not defined. The command terminates by displaying the following error message: %Configure eigrp router mode before redistributing
Examples
The following example shows how to configure a router to redistribute EIGRP routes into an EIGRP process:
Router# configure terminal Router(config)# router eigrp virtual-name Router(config-router)# redistribute eigrp 6473 metric 1 2 3 4 5The following example shows the behavior of the redistribution eigrpcommand when the EIGRP router is not defined in Cisco IOS Release 12.0(33)S:
Router# configure terminal Router(config)# router ospf 100 vrf vrf1 Router(config-router)# redistribute eigrp 99 %Configure eigrp router mode before redistributingredistribute maximum-prefix (EIGRP)
To limit the number of prefixes redistributed into an Enhanced Interior Gateway Routing Protocol (EIGRP) process, use the redistribute maximum-prefixcommand in address family configuration mode or address-family topology configuration mode. To disable this function, use the no form of this command.
redistribute maximum-prefix maximum [threshold] [ [dampened] [ reset-time minutes ] [ restart minutes ] [ restart-count number ] | [warning-only] ]
no redistribute maximum-prefix
Syntax Description
maximum
Maximum number of prefixes that are redistributed into EIGRP under an address family. The range for this argument is a number from 1 to 4294967295.
Note The number of prefixes that can be configured is limited only by the available system resources on the router.
threshold
(Optional) The prefix percentage number. Valid values are 1 to 100. The default is 75. This value causes the router to generate syslog warning messages when the specified percentage of the maximum-prefix limit has been exceeded.
dampened
(Optional) Configures a decay penalty to be applied to the restart-time period each time the maximum-prefix limit is exceeded. The half-life for the decay penalty is 150 percent of the default or user-defined restart-time value in minutes. This keyword is disabled by default.
reset-time minutes
(Optional) Configures the router to reset the restart count to 0 after the default or configured reset-time period has expired. The value for the minutes argument is from 1 to 65535 minutes. The default reset-time period is 15 minutes.
restart minutes
(Optional) Configures a time period in which the router will not form adjacencies or accept redistributed routes from the Routing Information Base (RIB) after the maximum-prefix limit has been exceeded. The value for the minutes argument is from 1 to 65535 minutes. The default restart-time period is 5 minutes.
restart-count number
(Optional) Configures the number of times a peering session can be automatically be reestablished after the peering session has been torn down or after a redistribute route has been cleared and relearned because the maximum-prefix limit has been exceeded. The default restart-count limit is 3.
Caution Once the restart count threshold has been crossed, you will need to enter the clear ip route * or clear ip eigrp neighborcommand to reestablish normal peering and/or redistribution.
warning-only
(Optional) Configures the router to generate syslog messages only when the maximum-prefix limit is reached, instead of suspending redistribution. This keyword is disabled by default.
Command Modes
Address family configuration (config-router-af) Address family topology configuration (config-router-af-topology)
Command History
Release
Modification
12.0(29)S
This command was introduced.
12.3(14)T
This command was integrated into Cisco IOS Release 12.3(14)T.
15.0(1)M
This command was modified. Address family topology configuration mode was added.
12.2(33)SRE
This command was integrated into Cisco IOS Release 12.2(33)SRE.
Cisco IOS XE Release 2.6
This command was integrated into Cisco IOS XE Release 2.6.
Usage Guidelines
The redistribute maximum-prefix command is used to configure limit prefixes learned through redistribution. When the maximum-prefix limit is exceeded, all routes learned from the RIB will be discarded and redistribution will be suspended for the default or user-defined time period. The maximum-prefix limit that can be configured for redistributed prefixes is limited only by the available system resources on the router.
Inherited Timer Values
Default or user-defined restart, restart-count, and reset-time values for the process-level configuration of this feature, configured with the maximum-prefix command, are inherited by the redistribute maximum-prefix (EIGRP) and neighbor maximum-prefix (EIGRP) command configurations by default. If a single peer is configured with the neighbor maximum-prefix(EIGRP) command, a process-level configuration or a configuration that is applied to all neighbors will be inherited.
Examples
The following example, starting in global configuration mode, configures the maximum prefix limit for routes learned through redistribution. The maximum limit is set to 5000 prefixes and the warning threshold is set to 95 percent. When the number of prefixes learned through redistribution reaches 4750 (95 percent of 5000), warning messages will be displayed in the console. Because the warning-only keyword was configured, the topology and routing tables will not be cleared and route redistribution will not be placed in a penalty state.
Router(config)# router eigrp 100 Router(config-router)# address-family ipv4 vrf RED Router(config-router-af)# redistribute maximum-prefix 5000 95 warning-only Router(config-router-af)# endThe following example shows this configuration in address-family topology configuration mode:
Router(config)# router eigrp virtual-name Router(config-router)# address-family ipv4 vrf RED autonomous-system 4453 Router(config-router-af)# network 172.16.0.0 Router(config-router-af)# topology base Router(config-router-af-topology)# redistribute maximum-prefix 5000 95 warning-only Router(config-router-af-topology)# exit-af-topologyRelated Commands
Command
Description
address-family (EIGRP)
Enters address-family configuration mode to configure an EIGRP routing instance.
clear ip eigrp neighbors
Deletes entries from the EIGRP neighbor table.
clear ip eigrp vrf neighbor
Deletes neighbor entries from the VRF table.
clear ip route
Deletes routes from the IP routing table.
network (EIGRP)
Specifies the network for an EIGRP routing process.
redistribute maximum-prefix (EIGRP)
Limits the number of prefixes redistributed into an EIGRP process.
topology (EIGRP)
Configures an EIGRP process to route IP traffic under the specified topology instance and enters address-family topology configuration mode.
remote-neighbors source (EIGRP)
To configure an Enhanced Interior Gateway Routing Protocol (EIGRP) process that enables remote neighbors to accept inbound connections from any remote IP address, use the remote-neighbors source command in address family configuration mode. To remove the configuration, use the no form of this command.
=remote-neighbors source interface-type interface-number { multicast-group group-address | unicast-listen lisp-encap [ lisp-top-id ] } [ allow-list access-list-name ] [ max-neighbor max-remote-peers ]
remote-neighbors source interface-type interface-number { multicast-group | unicast-listen lisp-encap [ lisp-top-id | [ allow-list access-list-name ] [ max-neighbor max-remote-peers ] ] }
Syntax Description
interface-type interface-number Interface to be used as the source for packets that are sent to remote neighbors.
multicast-group Uses IP multicast to discover remote neighbors and form remote neighbor relationships.
group-address Multicast address that EIGRP will use to discover remote neighbors and exchange information. Only devices using the same group address will discover one another as neighbors.
unicast-listen Accepts connections initiated by remote neighbors and forms remote neighbor relationships without having to manually configure the remote neighbor IP address.
lisp-encap Specifies that the data for this neighbor route will be Location/ID Separation Protocol (LISP) encapsulated.
lisp-top-id (Optional) Identity of the LISP instance. Only one LISP ID is allowed per device.
allow-list (Optional) Uses an Access Control List (ACL) to specify the remote IP addresses from which EIGRP neighbor connections may be accepted. If you do not use the allow-list keyword, then all IP addresses (permit any) will be accepted.
access-list-name (Optional) Name of the ACL to be used with the allow-list keyword.
max-neighbors (Optional) Uses the maximum number of remote neighbors. If you do not use this keyword, the maximum number of remote neighbors is limited only by the available memory and bandwidth.
max-remote-peers (Optional) Maximum number of remote neighbors that a member of the multicast group may accept. The range is from 1 to 65535. Command History
Release Modification Cisco IOS XE Release 3.10S
This command was introduced.
15.3(3)S
This command integrated into Cisco IOS Release 15.3(3)S.
Usage Guidelines
You can use this command to configure EIGRP peers to receive unicast or multicast peering updates.
Examples
The following example shows how to configure a customer edge router to receive unicast peering updates.
Device> enable Device# configure terminal Device(config)# router eigrp test Device(config-router)# address family ipv4 unicast autonomous-system 100 Device(config-router-af)# remote-neighbors source gigabitEthernet 0/0/1 unicast-listen lisp-encap 2router eigrp
To configure the Enhanced Interior Gateway Routing Protocol (EIGRP) routing process, use the router eigrp command in global configuration mode. To remove an EIGRP routing process, use the no form of this command.
router eigrp { autonomous-system-number | virtual-instance-name }
no router eigrp { autonomous-system-number | virtual-instance-name }
Syntax Description
autonomous-system-number
Autonomous system number that identifies the services to the other EIGRP address-family routers. It is also used to tag routing information. Valid range is 1 to 65535.
virtual-instance-name
EIGRP virtual instance name. This name must be unique among all address-family router processes on a single router, but need not be unique among routers.
Command History
Release
Modification
10.0
This command was introduced.
12.2(33)SRA
This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2(31)SB2
This command was integrated into Cisco IOS Release 12.2(31)SB2.
Cisco IOS XE Release 2.1
This command was integrated into Cisco IOS XE Release 2.1.
12.2SX
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware.
15.0(1)M
This command was modified. The virtual-instance-name argument was added.
12.2(33)SRE
This command was modified. The virtual-instance-name argument was added.
12.2(33)XNE
This command was modified. The virtual-instance-name argument was added.
Cisco IOS XE Release 2.5
This command was modified. The virtual-instance-name argument was added.
Usage Guidelines
Configuring the router eigrp command with the autonomous-system-numberargument creates an EIGRP configuration referred to as autonomous system (AS) configuration. An EIGRP AS configuration creates an EIGRP routing instance that can be used for tagging routing information.
Configuring the router eigrp command with the virtual-instance-name argument creates an EIGRP configuration referred to as EIGRP named configuration. An EIGRP named configuration does not create an EIGRP routing instance by itself. An EIGRP named configuration is a base configuration that is required to define address-family configurations under it that are used for routing.
route-tag list
To create a route tag list, use the route-tag list command in global configuration mode. To remove the route tag list, use the no form of this command.
route-tag list list-name { deny | permit | sequence number { deny | permit } } tag-value-dotted-decimal mask
no route-tag list list-name [ sequence number { deny | permit } tag-value-dotted-decimal mask ]
Syntax Description
list-name
Name of the route tag list.
deny
Specifies packets that have to be rejected.
permit
Specifies packets that have to be forwarded.
sequence
Specifies the sequence number of an entry.
number
Sequence number. The valid range is from 1 to 4294967294.
tag-value-dotted-decimal
Route tag value in dotted-decimal format.
mask
Wildcard mask.
Usage Guidelines
Use the route-tag list command to create route tag lists that will be used by route maps to match routes based on the criteria specified in the lists.
route-tag notation
To enable the display of route tag values in dotted-decimal format, use the route-tag notation command in global configuration mode. To disable this functionality, use the no form of this command.
Usage Guidelines
Configure the route-tag notation command to display route tag values in dotted-decimal format. When you configure this command, route tags are displayed as dotted decimals, irrespective of whether or not the route tags were configured as dotted decimals.
Examples
The following example shows how to configure the route-tag notation command:
Device(config)# route-tag notation dotted-decimalRelated Commands
Command
Description
eigrp default-route-tag
Sets a default route tag for all internal EIGRP routes.
match tag
Filters routes that match specified route tags.
set tag (IP)
Sets a tag value for routes.
show ip route
Displays contents of the IPv4 routing table.
show ipv6 route
Displays contents of the IPv6 routing table.
show route-map
Displays information about static and dynamic route maps.
show route-tag list
Displays information about route tag lists configured on the device.
