Table Of Contents

EIGRP Commands

auto-summary (EIGRP)

clear ip eigrp neighbors

default-information

default-metric (EIGRP)

distance eigrp

distribute-list in (RIP, IGRP, EIGRP)

distribute-list out (RIP, IGRP, EIGRP)

eigrp log-neighbor-changes

eigrp log-neighbor-warnings

eigrp router-id

eigrp stub

ip authentication key-chain eigrp

ip authentication mode eigrp

ip bandwidth-percent eigrp

ip hello-interval eigrp

ip hold-time eigrp

ip split-horizon eigrp

ip summary-address eigrp

metric weights (EIGRP)

neighbor (EIGRP)

network (EIGRP)

offset-list (EIGRP)

router eigrp

set metric (EIGRP)

show ip eigrp interfaces

show ip eigrp neighbors

show ip eigrp topology

show ip eigrp traffic

timers active-time

traffic-share balanced

variance (EIGRP)

EIGRP Commands

---

Use the commands in this chapter to configure and monitor Enhanced Interior Gateway Routing Protocol (EIGRP). For EIGRP configuration information and examples, refer to the "Configuring IP EIGRP" chapter of the Cisco IOS IP Configuration Guide.

auto-summary (EIGRP)

To restore the default behavior of automatic summarization of subnet routes into network-level routes, use the auto-summary command in router configuration mode. To disable this function and send subprefix routing information across classful network boundaries, use the no form of this command.

auto-summary

no auto-summary

Syntax Description

This command has no arguments or keywords.

Defaults

The behavior of this command is enabled by default (the software summarizes subprefixes to the classful network boundary when crossing classful network boundaries).

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Route summarization reduces the amount of routing information in the routing tables.

By default, Border Gateway Protocol (BGP) does not accept subnets redistributed from an Interior Gateway Protocol (IGP). To advertise and carry subnet routes in BGP, use an explicit network command or the no auto-summary command. If you disable automatic summarization and have not entered a network command, you will not advertise network routes for networks with subnet routes unless they contain a summary route.

Enhanced Interior Gateway Routing Protocol (EIGRP) summary routes are given an administrative distance value of 5. You cannot configure this value.

Routing Information Protocol (RIP) Version 1 always uses automatic summarization. If you are using RIP Version 2, you can turn off automatic summarization by specifying the no auto-summary command. Disable automatic summarization if you must perform routing between disconnected subnets. When automatic summarization is off, subnets are advertised.

Examples

The following example disables automatic summarization for EIGRP process 1:

router eigrp 1

 no auto-summary

Related Commands

Command	Description
ip summary-address eigrp	Configures a summary aggregate address for a specified interface.

clear ip eigrp neighbors

To delete entries from the neighbor table, use the clear ip eigrp neighbors command in EXEC mode.

clear ip eigrp neighbors [ip-address | interface-type interface-number]

Syntax Description

ip-address	(Optional) Address of the neighbor.
interface-type interface-number	(Optional) Interface type and number. Specifying these arguments removes the specified interface type from the neighbor table that all entries learned via this interface.

Command Modes

EXEC

Command History

Release	Modification
10.0	This command was introduced.

Examples

The following example removes the neighbor whose address is 172.16.8.3:

Router# clear ip eigrp neighbors 172.16.8.3

Related Commands

Command	Description
show ip eigrp interfaces	Displays information about interfaces configured for EIGRP.

default-information

To control the candidate default routing information between IGRP or Enhanced Interior Gateway Routing Protocol (EIGRP) processes, use the default-information command in router configuration mode. To suppress IGRP or EIGRP candidate information in incoming or outbound updates, use the no default-information in command.

default-information {in | out} {access-list-number | access-list-name}

no default-information {in | out}

Syntax Description

in	Allows IGRP or EIGRP exterior or default routes to be received by an IGRP process.
out	Allows IGRP or EIGRP exterior routes to be advertised in updates.
access-list-number | access-list-name	Number or name of an access list. It can be a number in the range from 1 to 99 or an access list name.

Defaults

Normally, exterior routes are always accepted and default information is passed between IGRP or EIGRP processes when redistribution occurs.

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.
11.2	The access-list-number and access-list-name arguments were added.

Usage Guidelines

The default network of 0.0.0.0 used by Routing Information Protocol (RIP) cannot be redistributed by IGRP but can be redistributed by EIGRP.

Examples

The following example allows IGRP exterior or default routes to be received by the IGRP process in autonomous system 1:

router igrp 1

 default-information in

The following example allows EIGRP exterior or default routes to be received by the EIGRP process in autonomous system :

router eigrp 1

 default-information in

default-metric (EIGRP)

To set metrics for IGRP or Enhanced Interior Gateway Routing Protocol (EIGRP), use the default-metric command in router configuration mode. To remove the metric value and restore the default state, use the no form of this command.

default-metric bandwidth delay reliability loading mtu

no default-metric bandwidth delay reliability loading mtu

Syntax Description

bandwidth	Minimum bandwidth of the route in kilobits per second. It can be from 1 to 4294967295.
delay	Route delay in tens of microseconds. It can be 1 or any positive number that is a multiple of 39.1 nanoseconds.
reliability	Likelihood of successful packet transmission expressed as a number between 0 and 255. The value 255 means 100 percent reliability; 0 means no reliability.
loading	Effective bandwidth of the route expressed as a number from 1 to 255 (255 is 100 percent loading).
mtu	Minimum maximum transmission unit (MTU) size of the route in bytes. It can be from 1 to 65535.

Defaults

Only connected routes can be redistributed without a default metric. the metric of redistributed Connected routes is set to 0.

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

A default metric is required to redistribute a protocol into IGRP or EIGRP, unless you use the redistribute command. Automatic metric translations occur between IGRP and EIGRP. You do not need default metrics to redistributed IGRP or EIGRP into itself.

---

Note The default metric command does not affect EIGRP-to-EIGRP or IGRP-to-EIGRP distribution. To configure EIGRP-to-EIGRP or IGRP-to-EIGRP distribution, use route maps.

---

Metric defaults have been carefully set to work for a wide variety of networks. Take great care when changing these values. Keeping the same metrics is supported only when redistributing from IGRP, EIGRP, or static routes.

---

Note When enabled, the default-metric command applies a metric value of 0 to redistributed connected routes. The default-metric command does not override metric values that are applied with the redistribute command.

---

Examples

The following example takes redistributed Routing Information Protocol (RIP) metrics and translates them into EIGRP metrics with values as follows: bandwidth = 1000, delay = 100, reliability = 250, loading = 100, and MTU = 1500.

router eigrp 1

 network 172.16.0.0

 redistribute rip

 default-metric 1000 100 250 100 1500

Related Commands

Command	Description
redistribute (IP)	Redistributes routes from one routing domain into another routing domain.

distance eigrp

To allow the use of two administrative distances—internal and external—that could be a better route to a node, use the distance eigrp command in router configuration mode. To reset these values to their defaults, use the no form of this command.

distance eigrp internal-distance external-distance

no distance eigrp

Syntax Description

internal-distance	Administrative distance for EIGRP internal routes. Internal routes are those that are learned from another entity within the same autonomous system. The distance can be a value from 1 to 255.
external-distance	Administrative distance for EIGRP external routes. External routes are those for which the best path is learned from a neighbor external to the autonomous system. The distance can be a value from 1 to 255.

Defaults

internal-distance: 90

external-distance: 170

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer from 0 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.

Use the distance eigrp command if another protocol is known to be able to provide a better route to a node than was actually learned via external EIGRP, or if some internal routes should really be preferred by EIGRP.

Table 19 lists the default administrative distances.

Table 19 Default Administrative Distances 

Route Source	Default Distance
Connected interface	0
Static route	1
EIGRP summary route	5
External BGP	20
Internal EIGRP	90
IGRP	100
Open Shortest Path First (OSPF)	110
Intermediate System-to-Intermediate System (IS-IS)	115
Routing Information Protocol (RIP)	120
Exterior Gateway Protocol (EGP)	140
EIGRP external route	170
Internal Border Gateway Protocol (BGP)	200
Unknown	255

To display the default administrative distance for a specified routing process, use the show ip protocols EXEC command.

Examples

In the following example, the router eigrp global configuration command sets up EIGRP routing in autonomous system number 1. The network router configuration commands specify EIGRP routing on networks 192.168.7.0 and 172.16.0.0. The distance eigrp command sets the administrative distance of all EIGRP internal routes to 80 and all EIGRP external routes to 130.

Router(config)# router eigrp 1

Router(router-config)# network 192.168.7.0

Router(router-config)# network 172.16.0.0 

Router(router-config)# distance eigrp 80 130 

---

Note You cannot set the administrative distance in EIGRP against certain routes or sources, as you can with other protocols. The command does not work this way with EIGRP.

---

Related Commands

Command	Description
show ip protocols	Displays the parameters and current state of the active routing protocol process.

distribute-list in (RIP, IGRP, EIGRP)

To filter networks received in updates, use the distribute-list in command in address family or router configuration mode. To disable this function, use the no form of this command.

distribute-list {access-list-number | prefix prefix-list-name [gateway prefix-list-name]} in [interface-type interface-number]

no distribute-list {access-list-number | prefix prefix-list-name [gateway prefix-list-name]} in [interface-type interface-number]

Syntax Description

access-list-number	Standard IP access list number. The list defines which networks are to be received and which are to be suppressed in routing updates.
prefix prefix-list-name	Name of a prefix list. The list defines which networks are to be received and which are to be suppressed in routing updates, based upon matching the network prefix to the prefixes in the list.
gateway prefix-list-name	(Optional) Name of the prefix list to be applied to the gateway of the prefix being updated.
in	Applies the access list to incoming routing updates.
interface-type	(Optional) Interface type.
interface-number	(Optional) Interface number on which the access list should be applied to incoming updates. If no interface is specified, the access list will be applied to all incoming updates.

Defaults

This command is disabled by default.

Command Modes

Address family configuration

Router configuration

Command History

Release	Modification
10.0	This command was introduced.
11.2	The access-list-number, interface-type, and interface-number arguments were added.
12.0	The prefix-list-name argument was added.
12.0(7)T	Address family configuration mode was added.

Usage Guidelines

This command is not supported in Intermediate System-to-Intermediate System (IS-IS) or Open Shortest Path First (OSPF).

Using a prefix list allows filtering based upon the prefix length, making it possible to filter either on the prefix list, the gateway, or both for incoming updates.

Specify either an access list or a prefix list with the distribute-list in command.

Use the gateway keyword only with the prefix-list keyword.

To suppress networks from being advertised in updates, use the distribute-list out command.

Examples

In the following example, the BGP routing process accepts only two networks—network 0.0.0.0 and network 172.18.0.0:

access-list 1 permit 0.0.0.0

access-list 1 permit 172.18.0.0

access-list 1 deny 0.0.0.0 255.255.255.255

router bgp 5000

 network 172.18.0.0

 distribute-list 1 in

In the following example, The RIP process accepts only prefixes with prefix lengths of /8 to /24:

ip prefix-list max24 seq 5 permit 0.0.0.0/0 ge 8 le 24

router rip

 network 172.18.0.0

 distribute-list prefix max24 in

In the following example, the RIP process filters on packet length and accepts routing updates from address 192.168.1.1 only:

ip prefix-list max24 seq 5 permit 0.0.0.0/0 ge 8 le 24

ip prefix-list allowlist seq5 permit 192.168.1.1/32

router rip

 network 172.18.0.0

 distribute-list prefix max24 gateway allowlist in

Related Commands

Command	Description
access-list (IP extended)	Defines an extended IP access list.
distribute-list out (RIP, IGRP, EIGRP)	Suppresses networks from being advertised in updates.
ip prefix-list	Creates an entry in a prefix list.
redistribute (IP)	Redistributes routes from one routing domain into another routing domain.

distribute-list out (RIP, IGRP, EIGRP)

To suppress networks from being advertised in updates, use the distribute-list out command in address family or router configuration mode. To disable this function, use the no form of this command.

distribute-list {access-list-number | prefix prefix-list-name [gateway prefix-list-name]} out [interface-name | routing-process | as-number]

no distribute-list {access-list-number | prefix prefix-list-name [gateway prefix-list-name]} out [interface-name | routing-process | as-number]

Syntax Description

access-list-number	Standard IP access list number. The list defines which networks are to be received and which are to be suppressed in routing updates.
prefix prefix-list-name	Name of a prefix list. The list defines which networks are to be received and which are to be suppressed in routing updates, based upon matching the network prefix to the prefixes in the list.
gateway prefix-list-name	(Optional) Name of the prefix list to be applied to the gateway of the prefix being updated.
out	Applies the access list to outgoing routing updates.
interface-name	(Optional) Name of a particular interface.
routing-process	(Optional) Name of a particular routing process, or the keyword static or connected.
as-number	(Optional) Autonomous system number.

Defaults

This command is disabled by default.

Command Modes

Address family configuration

Router configuration

Command History

Release	Modification
10.0	This command was introduced.
11.2	The access-list-number argument was added.
12.0	The prefix-list-name argument was added.
12.0(7)T	Address family configuration mode was added.

Usage Guidelines

When redistributing networks, a routing process name can be specified as an optional trailing argument to the distribute-list command. Specifying an argument causes the access list or prefix list to be applied to only those routes derived from the specified routing process. After the process-specific access list or prefix list is applied, any access list or prefix list specified by a distribute-list command without a process name argument will be applied. Addresses not specified in the distribute-list command will not be advertised in outgoing routing updates.

Specify either an access list or a prefix list with the distribute-list in command.

Use the gateway keyword only with the prefix-list keyword.

---

Note To filter networks received in updates, use the distribute-list in command.

---

Examples

The following example causes only one network (network 172.18.0.0) to be advertised by a RIP routing process:

access-list 1 permit 172.18.0.0

access-list 1 deny 0.0.0.0 255.255.255.255

router rip

 network 172.18.0.0

 distribute-list 1 out

Related Commands

Command	Description
access-list (IP extended)	Defines an extended IP access list.
distribute-list in (RIP, IGRP, EIGRP)	Filters networks received in updates.
ip prefix-list	Creates an entry in a prefix list.

eigrp log-neighbor-changes

To enable the logging of changes in Enhanced Interior Gateway Routing Protocol (EIGRP) neighbor adjacencies, use the eigrp log-neighbor-changes command in router configuration mode. To disable the logging of changes in EIGRP neighbor adjacencies, use the no form of this command.

eigrp log-neighbor-changes

no eigrp log-neighbor-changes

Syntax Description

This command has no arguments or keywords.

Defaults

Adjacency changes are logged.

Command Modes

Router configuration

Command History

Release	Modification
11.2	This command was introduced.

Usage Guidelines

This 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.

Examples

The following configuration disables logging of neighbor changes for EIGRP process 1:

router eigrp 1

 no eigrp log-neighbor-changes

The following onfiguration enables logging of neighbor changes for EIGRP process 1:

router eigrp 1

 eigrp log-neighbor-changes

eigrp log-neighbor-warnings

To enable the logging of Enhanced Interior Gateway Routing Protocol (EIGRP) neighbor warning messages, use the eigrp log-neighbor-warnings command in router configuration mode. To disable the logging of EIGRP neighbor warning messages, use the no form of this command.

eigrp log-neighbor-warnings [seconds]

no eigrp log-neighbor-warnings

Syntax Description

seconds

(Optional) The time interval (in seconds) between repeated neighbor warning messages. The range of seconds is from 1 to 65535.

Defaults

Neighbor warning messages are logged.

Command Modes

Router configuration

Command History

Release	Modification
12.0(5)	This command was introduced.

Usage Guidelines

When neighbor warning messages occur, they are logged by default. With this command, you can disable and enable neighbor warning messages, and configure the interval between repeated neighbor warning messages.

Examples

The following command will log neighbor warning messages for EIGRP process 1 and repeat the warning messages in 5-minute (300 seconds) intervals:

router eigrp 1

 eigrp log-neighbor-warnings 300

eigrp router-id

To set the router ID used by Enhanced Interior Gateway Routing Protocol (EIGRP) when communicating with its neighbors, use the eigrp router-id command in router configuration mode. To remove the configured router ID, use the no form of this command.

eigrp router-id ip-address

no eigrp router-id ip-address

Syntax Description

ip-address

Router ID in dotted decimal notation.

Defaults

EIGRP automatically selects an IP address to use as the router ID when an EIGRP process is started. The highest local IP address is selected and loopback interfaces are preferred. The router ID is not changed unless the EIGRP process is removed with the no router eigrp command or if the router ID is manually configured with the eigrp router-id command.

Command Modes

Address family configuration
Router configuration

Command History

Release	Modification
12.1	This command was introduced.

Usage Guidelines

The router ID is used to identify the originating router for external routes. If an external route is received with the local router ID, the route is discarded. The router ID can be configured with any IP address with two exceptions; 0.0.0.0 and 255.255.255.255 are not legal values and cannot be entered. A unique value should be configured for each router.

Examples

The following example configures 172.16.1.3 as a fixed router ID:

router eigrp 1

 eigrp router-id 172.16.1.3

eigrp stub

To configure a router as a stub using Enhanced Interior Gateway Routing Protocol (EIGRP), use the eigrp stub command in router configuration mode. To disable the EIGRP stub routing feature, use the no form of this command.

eigrp stub [receive-only | connected | static | summary | redistributed]

no eigrp stub [receive-only | connected | static | summary | redistributed]

Syntax Description

receive-only	(Optional) Sets the router as a receive-only neighbor.
connected	(Optional) Advertises connected routes.
static	(Optional) Advertises static routes.
summary	(Optional) Advertises summary routes.
redistributed	(Optional) Advertises redistributred routes from other protocols and autonomous systems.

Defaults

Stub routing is not enabled by default.

Command Modes

Router configuration

Command History

Release	Modification
12.0(7)T	This command was introduced.
12.0(15)S	This command was integrated into Cisco IOS Release 12.0(15)S.
12.2	Keyword redistributed was added.

Usage Guidelines

Use the eigrp stub command to configure a router as a stub where the router directs all IP traffic to a distribution router.

The eigrp stub command can be modified with several options, and these options can be used in any combination except for the receive-only keyword. The receive-only keyword will restrict the router from sharing any of its routes with any other router in that EIGRP autonomous system, and the receive-only keyword will not permit any other option to be specified because it prevents any type of route from being sent. The four other optional keywords (connected, static, summary, and redistributed) can be used in any combination but cannot be used with the receive-only keyword.

If any of these four keywords is used with the eigrp stub command, only the route types specified by the particular keyword(s) will be sent. Route types specified by the non-used keyword(s) will not be sent.

The connected keyword permits the EIGRP Stub Routing feature to send connected routes. If the connected routes are not covered by a network statement, it may be necessary to redistribute connected routes with the redistribute connected command under the EIGRP process. This option is enabled by default.

The static keyword permits the EIGRP Stub Routing feature to send static routes. Without the configuration of this option, EIGRP will not send any static routes, including internal static routes that normally would be automatically redistributed. It will still be necessary to redistribute static routes with the redistribute static command.

The summary keyword permits the EIGRP Stub Routing feature to send summary routes. Summary routes can be created manually with the summary address command or automatically at a major network border router with the auto-summary command enabled. This option is enabled by default.

The redistributed keyword permits the EIGRP Stub Routing feature to send other routing protocols and autonomous systems. Without the configuration of this option, EIGRP will not advertize redistributed routes.

---

Note Multi-access interfaces, such as ATM, Ethernet, Frame Relay, ISDN PRI, and X.25, are supported by the EIGRP Stub Routing feature only when all routers on that interface, except the hub, are configured as stub routers.

---

Examples

In the following example, the eigrp stub command is used to configure the router as a stub that advertises connected and summary routes:

router eigrp 1

network 10.0.0.0

eigrp stub

In the following example, the eigrp stub command is issued with the connected and static keywords to configure the router as a stub that advertises connected and static routes (sending summary routes will not be permitted):

router eigrp 1

network 10.0.0.0

eigrp stub connected static

In the following example, the eigrp stub command is issued with the receive-only keyword to configure the router as a receive-only neighbor (connected, summary, and static routes will not be sent):

router eigrp 1

network 10.0.0.0 eigrp 

eigrp stub receive-only

In the following example, the eigrp stub command is issued with the redistributed keyword to configure the router to advertize other protocols and autonomous systems:

router eigrp 1

network 10.0.0.0 eigrp 

eigrp stub redistributed

ip authentication key-chain eigrp

To enable authentication of Enhanced Interior Gateway Routing Protocol (EIGRP) packets, use the ip authentication key-chain eigrp command 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.

Defaults

No authentication is provided for EIGRP packets.

Command Modes

Interface configuration

Command History

Release	Modification
11.2 F	This command was introduced.

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 eigrp command 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.

Defaults

No authentication is provided for EIGRP packets.

Command Modes

Interface configuration

Command History

Release	Modification
11.2 F	This command was introduced.

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 1:

ip authentication mode eigrp 1 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 eigrp command 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.

Defaults

50 percent

Command Modes

Interface configuration

Command History

Release	Modification
11.2	This command was introduced.

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 1:

interface serial 0

 bandwidth 56

 ip bandwidth-percent eigrp 1 75

Related Commands

Command	Description
bandwidth (interface)	Sets a bandwidth value for an interface.

ip hello-interval eigrp

To configure the hello interval for the Enhanced Interior Gateway Routing Protocol (EIGRP) routing process designated by an autonomous system number, 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).

Defaults

For low-speed, nonbroadcast multiaccess (NBMA) networks: 60 seconds

For all other networks: 5 seconds

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

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:

interface ethernet 0

 ip hello-interval eigrp 1 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 a particular Enhanced Interior Gateway Routing Protocol (EIGRP) routing process designated by the autonomous system number, 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).

Defaults

For low-speed, nonbroadcast multiaccess (NBMA) networks: 180 seconds

For all other networks: 15 seconds

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

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:

interface ethernet 0

 ip hold-time eigrp 1 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 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.

Defaults

The behavior of this command is enabled by default.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

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 (IGRP)	Enables the split horizon mechanism.
neighbor (IGRP)	Defines a neighboring router with which to exchange routing information.

ip summary-address eigrp

To configure a summary aggregate address for a specified interface, use the ip summary-address eigrp command in interface configuration mode. To disable a configuration, use the no form of this command.

ip summary-address eigrp as-number network-address subnet-mask [admin-distance]

no ip summary-address eigrp as-number network-address subnet-mask [admin-distance]

Syntax Description

as-number	Autonomous system number.
network-address	IP summary aggregate address to apply to an interface.
subnet-mask	Subnet mask.
admin-distance	(Optional) Administrative distance. A value from 0 to 255.

Defaults

No summary aggregate addresses are predefined. The default administrative distance metric for EIGRP is 90.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.
12.0(7)T	The admin-distance argument was added.

Usage Guidelines

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.

Examples

The following example sets the IP summary aggregate address for Ethernet interface 0 with an administrative distance of 95:

interface ethernet 0

 ip summary-address eigrp 1 192.168.0.0 255.255.0.0 95

Related Commands

Command	Description
auto-summary (EIGRP)	Restores the default behavior of automatic summarization of subnet routes into network-level routes.

metric weights (EIGRP)

To allow the tuning of the IGRP or Enhanced Interior Gateway Routing Protocol (EIGRP) metric calculations, use the metric weights command in router configuration mode. To reset the values to their defaults, use the no form of this command.

metric weights tos k1 k2 k3 k4 k5

no metric weights

Syntax Description

tos	Type of service must always be zero.
k1k2 k3 k4 k5	Constants that convert an IGRP or EIGRP metric vector into a scalar quantity.

Defaults

tos: 0

k1: 1

k2: 0

k3: 1

k4: 0

k5: 0

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Use this command to alter the default behavior of IGRP routing and metric computation and allow the tuning of the IGRP metric calculation for a particular type of service (ToS).

If k5 equals 0, the composite IGRP or EIGRP metric is computed according to the following formula:

metric = [k1 * bandwidth + (k2 * bandwidth)/(256 - load) + k3 * delay]

If k5 does not equal zero, an additional operation is performed:

metric = metric * [k5/(reliability + k4)]

Bandwidth is inverse minimum bandwidth of the path in BPS scaled by a factor of 2.56 * 1012. The range is from a 1200-bps line to 10 terabits per second.

Delay is in units of 10 microseconds. The range of delay is from 10 microseconds to 168 seconds. A delay of all ones indicates that the network is unreachable.

The delay parameter is stored in a 32-bit field, in increments of 39.1 nanoseconds. The range of delay is from 1 (39.1 nanoseconds) to hexadecimal FFFFFFFF (decimal 4,294,967,040 nanoseconds). A delay of all ones (that is, a delay of hexadecimal FFFFFFFF) indicates that the network is unreachable.

Table 20 lists the default values used for several common media.