I through R

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 Default

No authentication is provided for EIGRP packets.

Command Modes

Interface configuration (config-if) Virtual network interface (config-if-vnet)

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 SPORTS

Related 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.

ip authentication mode eigrp as-number md5

no ip authentication mode eigrp as-number md5

Syntax Description

as-number

Autonomous system number.

md5

Keyed Message Digest 5 ( MD5) authentication.

Command Default

No authentication is provided for EIGRP packets.

Command Modes

Interface configuration (config-if) Virtual network interface (config-if-vnet)

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 md5

Related 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.

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.

ip bandwidth-percent eigrp as-number percent

no ip bandwidth-percent eigrp as-number percent

Syntax Description

as-number

Autonomous system number.

percent

Percent of bandwidth that EIGRP may use.

Command Default

EIGRP may use 50 percent of available bandwidth.

Command Modes

Interface configuration (config-if) Virtual network interface (config-if-vnet)

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.

Examples

The following example allows EIGRP to use up to 75 percent (42 kbps) of a 56-kbps serial link in autonomous system 209:

Router(config)# interface serial 0
Router(config-if)# bandwidth 56
Router(config-if)# ip bandwidth-percent eigrp 209 75

Related Commands

Command

Description

bandwidth (interface)

Sets a bandwidth value for an interface.

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.

ip hello-interval eigrp as-number seconds

no ip hello-interval eigrp as-number [seconds]

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 Modes

Interface configuration (config-if) Virtual network interface (config-if-vnet)

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.

Examples

The following example sets the hello interval for Ethernet interface 0 to 10 seconds:

Router(config)# interface ethernet 0
Router(config-if)# ip hello-interval eigrp 109 10

Related Commands

Command

Description

bandwidth (interface)

Sets a bandwidth value for an interface.

ip hold-time eigrp

Configures the hold time for a particular EIGRP routing process designated by the autonomous system number.

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.

ip hold-time eigrp as-number seconds

no ip hold-time eigrp as-number seconds

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 Modes

Interface configuration (config-if) Virtual network interface (config-if-vnet)

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.

Examples

The following example sets the hold time for Ethernet interface 0 to 40 seconds:

Router(config)# interface ethernet 0
Router(config-if)# ip hold-time eigrp 109 40

Related Commands

Command

Description

bandwidth (interface)

Sets a bandwidth value for an interface.

ip hello-interval eigrp

Configures the hello interval for the EIGRP routing process designated by an autonomous system number.

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 ]

Syntax Description

autonomous-system-number

Autonomous system number.

no-ecmp-mode

(Optional) Evaluates all paths to a network before advertising the paths out of an interface.

Command Default

The IP next-hop-self state is enabled.

Command Modes

Interface configuration (config-if)

Virtual network interface (config-if-vnet)

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-mode

Related Commands

Command

Description

ipv6 next-hop self eigrp

Instructs an EIGRP device that the IPv6 next hop is the local outbound interface.

next-hop-self

Enables EIGRP to advertise routes with the local outbound interface address as the next hop.

ip 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.

ip split-horizon eigrp as-number

no ip split-horizon eigrp as-number

Syntax Description

as-number

Autonomous system number.

Command Default

The behavior of this command is enabled by default.

Command Modes

Interface configuration (config-if) Virtual network interface (config-if-vnet)

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.


Note


In 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.


Examples

The following example disables split horizon on a serial link connected to an X.25 network:

interface serial 0
 encapsulation x25
 no ip split-horizon eigrp 101

Related Commands

Command

Description

ip split-horizon (RIP)

Enables the split horizon mechanism.

neighbor (EIGRP)

Defines a neighboring router with which to exchange routing information.

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 noform 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

as-number

Autonomous system number.

ip-address

Summary IP address to apply to an interface.

mask

Subnet mask.

admin-distance

(Optional) Administrative distance. Range: 0 to 255.

Note   

Starting with Cisco IOS XE Release 3.2S, the admin-distance argument was removed. Use the summary-metric command to configure the administrative distance.

leak-map name

(Optional) Specifies the route-map reference that is used to configure the route leaking through the summary.

Command Default

  • An administrative distance of 5 is applied to EIGRP summary routes.
  • EIGRP automatically summarizes to the network level, even for a single host route.
  • No summary addresses are predefined.
  • The default administrative distance metric for EIGRP is 90.

Command Modes

Interface configuration (config-if)

Virtual network interface (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 that 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 95 

The 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)# end
 

The 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 33

Related Commands

Command

Description

auto-summary (EIGRP)

Configures automatic summarization of subnet routes to network-level routes (default behavior).

summary-metric

Configures fixed metrics and administrative distance for an EIGRP summary aggregate address.

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.

match extcommunity extended-community-list-name

no match extcommunity extended-community-list-name

Syntax Description

extended-community-list-name

Name of an extended community list.

Command Default

BGP and EIGRP extended community list attributes are not matched.

Command Modes

Route-map configuration (config-route-map)

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 100

Related 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.

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.

metric maximum-hops hops-number

no metric maximum-hops

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 Default

The maximum number of hops is 100.

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 200

The 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 200

Related 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 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

tos

Type of service. This value must always be zero.

k1 k2 k3 k4 k5 k6

(Optional) Constants that convert an EIGRP metric vector into a scalar quantity. Valid values are 0 to 255. Given below are the default values:

  • k1: 1
  • k2: 0
  • k3: 1
  • k4: 0
  • k5: 0
  • k6: 0
Note   

In address family configuration mode, if the values are not specified, default values are configured. The k6 argument is supported only in address family configuration mode.

Command Default

EIGRP metric K values are set to their default values.

Command Modes

Router configuration (config-router)

Address family configuration (config-router-af)

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 0

The 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 1

Related 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 router with which a router that is running the Enhanced Interior Gateway Routing Protocol (EIGRP) 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 ]

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 through which peering sessions are established.

interface-number

Number of the interface or subinterface.

remote

(Optional) Specifies that the neighbor is remote. This keyword is available only for loopback interfaces.

maximum-hops

(Optional) Maximum hop count. Valid range is from 2 to 100. This argument is available only when the remote keyword is configured.

Command Default

No neighboring routers are defined.

Command Modes

Router configuration (config-router)

Address family configuration (config-router-af)

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.

Usage Guidelines

Multiple neighbor statements can be used to establish peering sessions with specific EIGRP neighbors. The interface through which EIGRP will exchange 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.


Note


Configuring 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 1/1

The 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 10

Related 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)

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.

network ip-address [wildcard-mask]

no network ip-address [wildcard-mask]

Syntax Description

ip-address

IP address of the directly connected network.

wildcard-mask

(Optional) Wildcard mask.

Command Default

No networks are specified.

Command Modes

Router configuration (config-router) Address-family configuration (config-router-af)

Command History

Release

Modification

10.0

This command was introduced.

12.0(4)T

The network-maskargument 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 (networkcommands) that can be configured on a router.

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

The 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 192.168.0.0

Related Commands

Command

Description

address-family (EIGRP)

Enters address-family configuration mode to configure an EIGRP routing instance.

router eigrp

Configures the EIGRP address-family process.

 
      

next-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.

next-hop-self

no next-hop-self [ no-ecmp-mode ]

Syntax Description

no-ecmp-mode

(Optional) Evaluates all paths to a network before advertising the paths out of an interface.

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 Modes

Address family interface (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.

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-mode

The 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-mode

Related Commands

Command

Description

address-family

Configures an EIGRP routing instance in address family configuration mode.

router eigrp

Configures an EIGRP routing process.

split-horizon (EIGRP)

Enables EIGRP split horizon.

nsf (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.

nsf

no nsf

Syntax Description

This command has no arguments or keywords.

Command Default

EIGRP NSF is disabled.

Command Modes

Router configuration (config-router)

Address family configuration (config-router-af)

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)# end  

The 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)# end 

Related 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 10

In 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 0

In 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 ethernet0

passive-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 Default

Hello packets and routing updates are sent and received on the interface.

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.

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 ethernet0/0

The 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 ethernet0/0 

The 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-interface

Related 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.

router 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 Default

No EIGRP processes are configured.

Command Modes

Global configuration (config)

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.

Examples

The following example configures EIGRP process 109:

Router(config)# router eigrp 109

The following example configures an EIGRP address-family routing process and assigns it the name “virtual-name”:

Router(config)# 
router eigrp virtual-name

Related Commands

Command

Description

network (EIGRP)

Specifies a list of networks for the EIGRP process.