Table Of Contents
ip authentication key-chain eigrp
EIGRP Commands
Use the commands in this chapter to configure and monitor Enhanced Interior Gateway Routing Protocol (EIGRP). For configuration information and examples, refer to the "Configuring EIGRP" chapter of the Network Protocols Configuration Guide, Part 1.
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 transmit 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
Usage Guidelines
Route summarization reduces the amount of routing information in the routing tables.
By default, BGP does not accept subnets redistributed from IGP. To advertise and carry subnet routes in BGP, use an explicit network command or the no auto-summary command. If you disable auto-summarization and have not entered a network command, you will not advertise network routes for networks with subnet routes unless they contain a summary route.
EIGRP summary routes are given an administrative
value of 5. You cannot configure this value.
RIP Version 1 always uses automatic summarization. If you are using RIP Version 2, you can turn off automatic summarization by specifying no auto-summary. 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 process eigrp 109:
router eigrp 109no auto-summaryRelated Commands
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 | type number]
Syntax Description
Command Modes
EXEC
Command History
Examples
The following example removes the neighbor whose address is 160.20.8.3:
Router# clear ip eigrp neighbors 160.20.8.3Related Commands
default-information
To control the candidate default routing information between IGRP or 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 | name}
no default-information {in | out}
Syntax Description
Defaults
Normally, exterior routes are always accepted and default information is passed between IGRP or EIGRP processes when doing redistribution.
Command Modes
Router configuration
Command History
10.0
This command was introduced.
11.2
The access-list-number and name arguments were added.
Usage Guidelines
The default network of 0.0.0.0 used by RIP cannot be redistributed by IGRP or EIGRP.
Examples
The following example allows IGRP exterior or default routes to be received by the IGRP process in autonomous system 23:
router igrp 23default-information inThe following example allows EIGRP exterior or default routes to be received by the EIGRP process in autonomous system 23:
router eigrp 23default-information indefault-metric (EIGRP)
To set metrics for IGRP or EIGRP, use this form of 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
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
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.
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 RIP metrics and translates them into IGRP metrics with values as follows: bandwidth = 1000, delay = 100, reliability = 250, loading = 100, and mtu =1500.
router igrp 109network 131.108.0.0redistribute ripdefault-metric 1000 100 250 100 1500Related Commands
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
Defaults
internal-distance: 90
external-distance: 170
Command Modes
Router configuration
Command History
Usage Guidelines
An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.
Use the distance eigrp command if another protocol is known to be able to provide a better route to a node than was actually learned via external EIGRP or if some internal routes should really be preferred by EIGRP.
Table 29 lists the default administrative distances.
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 109. 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 109Router(router-config)# network 192.168.7.0Router(router-config)# network 172.16.0.0Router(router-config)# distance eigrp 80 130
Note
Related Commands
show ip protocols
Displays the parameters and current state of the active routing protocol process.
eigrp log-neighbor-changes
To enable the logging of changes in EIGRP neighbor adjacencies, use the eigrp log-neighbor-change 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 not arguments or keywords.
Defaults
No adjacency changes are logged.
Command Modes
Router configuration
Command History
Usage Guidelines
The configuration of this command enables the logging of neighbor adjacency changes to monitor the stability of the routing system and to help detect problems.
Examples
The following configuration will log neighbor changes for EIGRP process 209:
router eigrp 209eigrp log-neighbor-changesip authentication key-chain eigrp
To enable authentication of 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 autonomous-system key-chain
no ip authentication key-chain eigrp autonomous-system key-chain
Syntax Description
autonomous-system
Autonomous system 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
Examples
The following example applies authentication to autonomous system 2 and identifies a key chain named SPORTS:
ip authentication key-chain eigrp 2 SPORTSRelated Commands
ip authentication mode eigrp
To specify the type of authentication used in 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 autonomous-system md5
no ip authentication mode eigrp autonomous-system md5
Syntax Description
Defaults
No authentication is provided for EIGRP packets.
Command Modes
Interface configuration
Command History
Usage Guidelines
Configure authentication to prevent unapproved sources from introducing unauthorized or false routing messages. When authentication is configured, an MD5 keyed digest is added to each EIGRP packet in the specified autonomous system.
Examples
The following example configures the interface to use MD5 authentication in EIGRP packets in autonomous system 10:
ip authentication mode eigrp 10 md5Related Commands
ip bandwidth-percent eigrp
To configure the percentage of bandwidth that may be used by 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
Defaults
50 percent
Command Modes
Interface configuration
Command History
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; this 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:
interface serial 0bandwidth 56ip bandwidth-percent eigrp 209 75Related Commands
ip hello-interval eigrp
To configure the hello interval for the 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 autonomous-system-number seconds
no ip hello-interval eigrp autonomous-system-number seconds
Syntax Description
Defaults
For low-speed, NBMA networks: 60 seconds
For all other networks: 5 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
The default of 60 seconds applies only to low-speed, nonbroadcast, multiaccess (NBMA) media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command. Note that for the purposes of EIGRP, Frame Relay and SMDS networks may or may not be considered to be NBMA. These networks are considered NBMA if the interface has not been configured to use physical multicasting; otherwise, they are considered not to be NBMA.
Examples
The following example sets the hello interval for Ethernet interface 0 to 10 seconds:
interface ethernet 0ip hello-interval eigrp 109 10Related Commands
bandwidth
Sets a bandwidth value for an interface.
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 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 autonomous-system-number seconds
no ip hold-time eigrp autonomous-system-number seconds
Syntax Description
Defaults
For low-speed, NBMA networks: 180 seconds
For all other networks: 15 seconds
Command Modes
Interface configuration
Command History
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, nonbroadcast, multiaccess (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 0ip hold-time eigrp 109 40Related Commands
bandwidth
Sets a bandwidth value for an interface.
Configures the hello interval for the EIGRP routing process designated by an autonomous system number.
ip split-horizon eigrp
To enable 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 autonomous-system-number
no ip split-horizon eigrp autonomous-system-number
Syntax Description
Defaults
The behavior of this command is enabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
For networks that include links over X.25 PSNs, you can use the neighbor router configuration command to defeat the split horizon feature. As an alternative, you can explicitly specify the no ip split-horizon eigrp command in your configuration. However, if you do so, you must similarly disable split horizon for all routers and access servers in any relevant multicast groups on that network.
Note
Examples
The following example disables split horizon on a serial link connected to an X.25 network:
interface serial 0encapsulation x25no ip split-horizon eigrp 101Related Commands
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 autonomous-system-number address mask
no ip summary-address eigrp autonomous-system-number address mask
Syntax Description
autonomous-system-number
Autonomous system number.
address
IP summary aggregate address to apply to an interface.
mask
Subnet mask.
Defaults
No summary aggregate addresses are predefined.
Command Modes
Interface configuration
Command History
Usage Guidelines
EIGRP summary routes are given an administrative distance value of 5. You cannot configure this value.
Examples
The following example sets the IP summary aggregate address for Ethernet interface 0:
interface ethernet 0ip summary-address eigrp 109 192.1.0.0 255.255.0.0Related Commands
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 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
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 done:
metric = metric * [k5 / (reliability + k4)]Bandwidth is inverse minimum bandwidth of the path in bits per second scaled by a factor of 2.56 ¥ 1012. The range is from a 1200-bps line to 10 terabits per second.
Delay is in units of 10 microseconds. This gives a range of 10 microseconds to 168 seconds. A delay of all ones indicates that the network is unreachable.
The delay parameter is stored in a 32-bit field, in increments of 39.1 nanoseconds. This gives a range of 1 (39.1 nanoseconds) to hexadecimal FFFFFFFF (decimal 4,294,967,040 nanoseconds). A delay of all ones (that is, a delay of hexadecimal FFFFFFFF) indicates that the network is unreachable.
Table 30 lists the default values used for several common media.
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 sets the metric weights to slightly different values than the defaults:
router igrp 109network 131.108.0.0metric weights 0 2 0 2 0 0Related Commands
neighbor (EIGRP)
To define a neighboring router with which to exchange routing information, use this form of the neighbor command in router configuration mode. To remove an entry, use the no form of this command.
neighbor ip-address
no neighbor ip-address
Syntax Description
Defaults
No neighboring routers are defined.
Command Modes
Router configuration
Command History
Usage Guidelines
This command permits the point-to-point (nonbroadcast) exchange of routing information. When used in combination with the passive-interface router configuration command, routing information can be exchanged between a subset of routers and access servers on a LAN.
Multiple neighbor commands can be used to specify additional neighbors or peers.
Examples
In the following example, EIGRP updates are sent to all interfaces on network 192.168.0.0 except interface Ethernet 1. However, in this case a neighbor router configuration command is included. This command permits the sending of routing updates to specific neighbors. One copy of the routing update is generated per neighbor.
router eigrp 109network 192.168.0.0passive-interface ethernet 1neighbor 192.168.20.4Related Commands
network (EIGRP)
To specify a list of networks for the EIGRP routing process, use this form of the network command in router configuration mode. To remove an entry, use the no form of this command.
network network-number
no network network-number
Syntax Description
Defaults
No networks are specified.
Command Modes
Router configuration
Command History
Usage Guidelines
The network number specified must not contain any subnet information. There is no limit to the number of network commands you can use on the router.
IGRP or EIGRP sends updates to the interfaces in the specified network(s). Also, if an interface's network is not specified, it will not be advertised in any IGRP or EIGRP update.
The network mask can be as specific as the interface mask.
Examples
The following example configures a router for IGRP and assigns autonomous system 109. The network commands indicate the networks directly connected to the router.
router igrp 109network 131.108.0.0network 192.31.7.0Related Commands
Configures the EIGRP routing process.
router igrp
Configures the IGRP routing process.
offset-list (EIGRP)
To add an offset to incoming and outgoing metrics to routes learned via EIGRP, use the offset-list command in router configuration mode. To remove an offset list, use the no form of this command.
offset-list {access-list-number | name} {in | out} offset [type number]
no offset-list {access-list-number | name} {in | out} offset [type number]
Syntax Description
Defaults
This command is disabled by default.
Command Modes
Router configuration
Command History
10.0
This command was introduced.
10.3
The type and number arguments were added.
11.2
The name argument 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 extended offset-list's offset is added to the metric.
Examples
In the following example, the router applies an offset of 10 to the router's delay component only to access list 21:
offset-list 21 out 10In the following example, the router applies an offset of 10 to routes learned from Ethernet interface 0:
offset-list 21 in 10 ethernet 0router eigrp
To configure the EIGRP routing process, use the router eigrp command in global configuration mode. To shut down a routing process, use the no form of this command.
router eigrp autonomous-system
no router eigrp autonomous-system
Syntax Description
autonomous-system
Autonomous system number that identifies the routes to the other EIGRP routers. It is also used to tag the routing information.
Defaults
This command is disabled by default.
Command Modes
Global configuration
Command History
Examples
The following example configures an EIGRP routing process and assigns process number 109:
router eigrp 109Related Commands
set metric (EIGRP)
To set the metric value for EIGRP in a route-map, use the set metric route-map configuration command. To return to the default metric value, use the no form of this command.
set metric bandwidth delay reliability loading mtu
no set metric bandwidth delay reliability loading mtu
Syntax Description
Defaults
No metric will be set in the route-map.
Command Modes
Route-map configuration
Command History
Usage Guidelines
We recommend you consult your Cisco technical support representative before changing the default value.
Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.
Examples
The following example sets the bandwidth to 10,000, the delay to 10, the reliability to 255, the loading to 1, and the MTU to 1500:
set metric 10000 10 255 1 1500show ip eigrp interfaces
To display information about interfaces configured for EIGRP, use the show ip eigrp interfaces command in EXEC mode.
show ip eigrp interfaces [type number] [as-number]
Syntax Description
type
(Optional) Interface type.
number
(Optional) Interface number.
as-number
(Optional) Autonomous system number.
Command Modes
EXEC
Command History
Usage Guidelines
Use the show ip eigrp interfaces command to determine on which interfaces EIGRP is active, and to find out information about EIGRP relating to those interfaces.
If an interface is specified, only that interface is displayed. Otherwise, all interfaces on which EIGRP is running are displayed.
If an autonomous system is specified, only the routing process for the specified autonomous system is displayed. Otherwise, all EIGRP processes are displayed.
Examples
The following is sample output from the show ip eigrp interfaces command:
Router# show ip eigrp interfacesIP EIGRP interfaces for process 109Xmit Queue Mean Pacing Time Multicast PendingInterface Peers Un/Reliable SRTT Un/Reliable Flow Timer RoutesDi0 0 0/0 0 11/434 0 0Et0 1 0/0 337 0/10 0 0SE0:1.16 1 0/0 10 1/63 103 0Tu0 1 0/0 330 0/16 0 0Table 31 describes the fields in the display.
Related Commands
show ip eigrp neighbors
To display the neighbors discovered by Enhanced Interior Gateway Routing Protocol (EIGRP), use the show ip eigrp neighbors command in EXEC mode.
show ip eigrp neighbors [type number]
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
Use the show ip eigrp neighbors command to determine when neighbors become a
