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
variance (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 Cisco IOS IP and IP Routing 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, 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 distance 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 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 109:
Related 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
ip-address
|
(Optional) Address of the neighbor.
|
type number
|
(Optional) Interface type and number. Specifying these arguments removes 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 160.20.8.3:
Router# clear ip eigrp neighbors 160.20.8.3
Related 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
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 | name
|
Number or name of an access list. It can be a number in the range 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 doing redistribution.
Command Modes
Router configuration
Command History
Release
|
Modification
|
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 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 23:
The following example allows EIGRP exterior or default routes to be received by the EIGRP process in autonomous system 23:
default-metric (EIGRP)
To set metrics for Interior Gateway Routing Protocol (IGRP) or 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 RIP metrics and translates them into IGRP metrics with values as follows: bandwidth = 1000, delay = 100, reliability = 250, loading = 100, and mtu =1500.
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 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 59 lists the default administrative distances.
Table 59 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
|
OSPF
|
110
|
IS-IS
|
115
|
RIP
|
120
|
EGP
|
140
|
EIGRP external route
|
170
|
Internal 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 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 109
Router(config-router)# network 192.168.7.0
Router(config-router)# network 172.16.0.0
Router(config-router)# distance eigrp 80 130
Router(config-router)# 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 131.108.0.0:
access-list 1 permit 0.0.0.0
access-list 1 permit 131.108.0.0
access-list 1 deny 0.0.0.0 255.255.255.255
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
distribute-list prefix max24 in
In the following example, the RIP process filters on packet length and accepts routing updates from address 192.1.1.1 only:
ip prefix-list max24 seq 5 permit 0.0.0.0/0 ge 8 le 24
ip prefix-list allowlist seq5 permit 192.1.1.1/32
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 131.108.0.0) to be advertised by a RIP routing process:
access-list 1 permit 131.108.0.0
access-list 1 deny 0.0.0.0 255.255.255.255
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-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 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 209:
no eigrp log-neighbor-changes
The following configuration enables logging of neighbor changes for EIGRP process 209:
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-changes
Syntax Description
seconds
|
(Optional) The time interval in seconds between repeated neighbor warning messages. The range of seconds is 1-65535.
|
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 209 and repeat the warning messages in 5-minute (300 seconds) intervals:
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:
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]
no eigrp stub [receive-only | connected | static | summary]
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.
|
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.
|
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 three other optional keywords (connected, static, and summary) can be used in any combination but cannot be used with the receive-only keyword. If any of these three keywords is used individually with the eigrp stub command, connected and summary routes will not be sent automatically.
The connected keyword will permit 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 will permit 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 will permit 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.
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:
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):
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):
ip authentication key-chain eigrp
To enable authentication of Enhanced Interior Gateway Routing Protocol (IGRP) packets, use the ip authentication key-chain eigrp interface configuration command. 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
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 interface configuration command. 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
autonomous-system
|
Autonomous system number.
|
md5
|
Keyed 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 Message Digest 5 (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 eigrp interface configuration command. 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; 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:
ip bandwidth-percent eigrp 209 75
Related Commands
Command
|
Description
|
bandwidth
|
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 interface configuration command. To restore the default value, use the no form of this command.
ip hello-interval eigrp autonomous-system-number seconds
no ip hello-interval eigrp autonomous-system-number seconds
Syntax Description
autonomous-system-number
|
Autonomous system number.
|
seconds
|
Hello interval, in seconds.
|
Defaults
For low-speed, 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, 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:
ip hello-interval eigrp 109 10
Related Commands
Command
|
Description
|
bandwidth
|
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 interface configuration command. To restore the default value, use the no form of this command.
ip hold-time eigrp autonomous-system-number seconds
no ip hold-time eigrp autonomous-system-number seconds
Syntax Description
autonomous-system-number
|
Autonomous system number.
|
seconds
|
Hold time, in seconds.
|
Defaults
For low-speed, 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, 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:
ip hold-time eigrp 109 40
Related Commands
Command
|
Description
|
bandwidth
|
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 interface configuration command. To disable split horizon, use the no form of this command.
ip split-horizon eigrp autonomous-system-number
no ip split-horizon eigrp autonomous-system-number
Syntax Description
autonomous-system-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 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, it is recommended that you not change the default state of split horizon unless you are certain that your application requires the change in order to properly advertise routes. Remember that if split horizon is disabled on a serial interface and that interface is attached to a packet-switched network, you must disable split horizon for all routers 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:
no ip split-horizon eigrp 101
Related Commands
Command
|
Description
|
ip split-horizon (EIGRP)
|
Enables the split horizon mechanism.
|
neighbor (EIGRP)
|
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 interface configuration command. To disable a configuration, use the no form of this command.
ip summary-address eigrp autonomous-system-number network-address subnet-mask
[admin-distance]
no ip summary-address eigrp autonomous-system-number network-address subnet-mask
[admin-distance]
Syntax Description
autonomous-system-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 Enhanced Interior Gateway Routing Protocol (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:
ip summary-address eigrp 109 192.1.0.0 255.255.0.0 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 Interior Gateway Routing Protocol (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 EIGRP or IGRP routing and metric computation and allow the tuning of the 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 60 lists the default values used for several common media.
Table 60 Bandwidth Values by Media Type
Media Type
|
Delay
|
Bandwidth
|
Satellite
|
5120 (2 seconds)
|
5120 (500 megabits)
|
Ethernet
|
25600 (1 milliseconds [ms])
|
256000 (10 megabits)
|
1.544 Mbps
|
512000 (20,000 ms)
|
1,657,856 bits
|
64 kbps
|
512000 (20,000 ms)
|
40,000,000 bits
|
56 kbps
|
512000 (20,000 ms)
|
45,714,176 bits
|
10 kbps
|
512000 (20,000 ms)
|
256,000,000 bits
|
1 kbps
|
512000 (20,000 ms)
|
2,560,000,000 bits
|
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:
metric weights 0 2 0 2 0 0
Related Commands
Command
|
Description
|
bandwidth
|
Sets a bandwidth value for an interface.
|
delay
|
Sets a delay value for an interface.
|
metric holddown
|
Keeps new EIGRP routing information from being used for a certain period of time.
|
metric maximum-hops
|
Causes the IP routing software to advertise as unreachable those routes with a hop count higher than is specified by the command (IGRP only).
|
neighbor (EIGRP)
To define a neighboring router with which to exchange routing information, use the neighbor router configuration command. To remove an entry, use the no form of this command.
neighbor ip-address
no neighbor ip-address
Syntax Description
ip-address
|
IP address of a peer router with which routing information will be exchanged.
|
Defaults
No neighboring routers are defined.
Command Modes
Router configuration
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
Usage Guidelines
Multiple neighbor commands can be used to specify additional neighbors or peers.
With most routing protocols, the passive-interface command restricts outgoing advertisements only. However, when used with the Enhanced Interior Gateway Routing Protocol (EIGRP), the use of the passive-interface command suppresses the exchange of hello messages between two routers, which results in the loss of their neighbor relationship. This behavior stops not only routing updates from being advertised, but it also suppresses incoming routing updates.
Examples
In the following example, EIGRP permits the sending of routing updates to specific neighbors. One copy of the routing update is generated per neighbor.
Related Commands
Command
|
Description
|
passive-interface
|
Disables sending routing updates on an interface.
|
network (EIGRP)
To specify a list of networks for the Enhanced Interior Gateway Routing Protocol (EIGRP) routing process, use the network command in router configuration mode. To remove an entry, use the no form of this command.
network network-number [network-mask]
no network network-number [network-mask]
Syntax Description
network-number
|
IP address of the directly connected networks.
|
network-mask
|
(Optional) Network mask.
|
Defaults
No networks are specified.
Command Modes
Router configuration
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
12.0(4)T
|
The network-mask argument was added.
|
Usage Guidelines
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 networks. Also, if the network of an interface 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.
Related Commands
Command
|
Description
|
router eigrp
|
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 Enhanced Interior Gateway Routing Protocol (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
access-list-number | name
|
Standard access list number or name to be applied. Access list number 0 indicates all access lists. If offset is 0, no action is taken. For IGRP, the offset is added to the delay component only.
|
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.
|
type
|
(Optional) Interface type to which the offset-list is applied.
|
number
|
(Optional) Interface number to which the offset-list is applied.
|
Defaults
This command is disabled by default.
Command Modes
Router configuration
Command History
Release
|
Modification
|
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:
In the following example, the router applies an offset of 10 to routes learned from Ethernet interface 0:
offset-list 21 in 10 ethernet 0
router eigrp
To configure the Enhanced Interior Gateway Routing Protocol (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
Release
|
Modification
|
10.0
|
This command was introduced.
|
Examples
The following example configures an EIGRP routing process and assigns process number 109:
Related Commands
Command
|
Description
|
network (EIGRP)
|
Specifies a list of networks for the EIGRP routing process.
|
set metric (EIGRP)
To set the metric value for Enhanced Interior Gateway Routing Protocol (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
bandwidth
|
Metric value or EIGRP bandwidth of the route in kilobytes per second. It can be in the range 0 to 4294967295.
|
delay
|
Route delay in tens of microseconds. It can be in the range from 0 to 4294967295.
|
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 0 to 255 (255 is 100 percent loading).
|
mtu
|
Minimum maximum transmission unit (MTU) size of the route in bytes. It can be in the range 0 to 4294967295.
|
Defaults
No metric will be set in the route map.
Command Modes
Route-map configuration
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
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 1500
show ip eigrp interfaces
To display information about interfaces configured for Enhanced Interior Gateway Routing Protocol (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
Release
|
Modification
|
11.2
|
This command was introduced.
|
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 interfaces
IP EIGRP interfaces for process 109
Xmit Queue Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes
SE0:1.16 1 0/0 10 1/63 103 0
Table 61 describes the fields in the display.
Table 61 show ip eigrp interfaces Field Descriptions
Field
|
Description
|
Interface
|
Interface over which EIGRP is configured.
|
Peers
|
Number of directly connected EIGRP neighbors.
|
Xmit Queue Un/Reliable
|
Number of packets remaining in the Unreliable and Reliable transmit queues.
|
Mean SRTT
|
Mean smooth round-trip time (SRTT) interval (in milliseconds).
|
Pacing Time Un/Reliable
|
Pacing time used to determine when EIGRP packets should be sent out the interface (Unreliable and Reliable packets).
|
Multicast Flow Timer
|
Maximum number of seconds in which router will send multicast EIGRP packets.
|
Pending Routes
|
Number of routes in the packets sitting in the transmit queue waiting to be sent.
|
Related Commands
Command
|
Description
|
show ip eigrp neighbors
|
Displays the neighbors discovered by EIGRP.
|
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 [interface-type | autonomous-system-number | static]
Syntax Description
interface-type
|
(Optional) Interface type.
|
autonomous-system-number
|
(Optional) Autonomous system number.
|
static
|
(Optional) Static routes.
|
Command Modes
EXEC
Command History
Release
|
Modification
|
10.3
|
This command was introduced.
|
12.0(7)T
|
The static key word was added.
|
Usage Guidelines
Use the show ip eigrp neighbors command to determine when neighbors become active and inactive. It is also useful for debugging certain types of transport problems.
Examples
The following is sample output from the show ip eigrp neighbors command:
Router# show ip eigrp neighbors
IP-EIGRP Neighbors for process 77
Address Interface Holdtime Uptime Q Seq SRTT RTO
(secs) (h:m:s) Count Num (ms) (ms)
160.89.81.28 Ethernet1 13 0:00:41 0 11 4 20
160.89.80.28 Ethernet0 14 0:02:01 0 10 12 24
160.89.80.31 Ethernet0 12 0:02:02 0 4 5 20
Table 62 describes the significant fields shown in the display.
Table 62 show ip eigrp neighbors Field Descriptions
Field
|
Description
|
process 77
|
Autonomous system number specified in the router configuration command.
|
Address
|
IP address of the EIGRP peer.
|
Interface
|
Interface on which the router is receiving hello packets from the peer.
|
Holdtime
|
Length of time, in seconds, that the Cisco IOS software will wait to hear from the peer before declaring it down. If the peer is using the default hold time, this number will be less than 15. If the peer configures a nondefault hold time, the nondefault holdtime will be displayed.
|
Uptime
|
Elapsed time (in hours:minutes: seconds) since the local router first heard from this neighbor.
|
Q Count
|
Number of EIGRP packets (update, query, and reply) that the software is waiting to send.
|
Seq Num
|
Sequence number of the last Update, Query, or Reply packet that was received from this neighbor.
|
SRTT
|
Smooth round-trip time. This is the number of milliseconds it takes for an EIGRP packet to be sent to this neighbor and for the local router to receive an acknowledgment of that packet.
|
RTO
|
Retransmission timeout, in milliseconds. This is the amount of time the software waits before resending a packet from the retransmission queue to a neighbor.
|
show ip eigrp topology
To display entries in the Enhanced Interior Gateway Routing Protocol (EIGRP) topology table, use the show ip eigrp topology command in EXEC mode.
show ip eigrp topology [as-number | [[ip-address] mask]] [active | all-links | pending | summary
| zero-successors]
Syntax Description
as-number
|
(Optional) Autonomous system number.
|
ip-address
|
(Optional) IP address. When specified with a mask, a detailed description of the entry is provided.
|
mask
|
(Optional) Subnet mask.
|
active
|
(Optional) Displays only active entries in the EIGRP topology table.
|
all-links
|
(Optional) Displays all entries in the EIGRP topology table.
|
pending
|
(Optional) Displays all entries in the EIGRP topology table that are waiting for an update from a neighbor or are waiting to reply to a neighbor.
|
summary
|
(Optional) Displays a summary of the EIGRP topology table.
|
zero-successors
|
(Optional) Displays available routes in the EIGRP topology table.
|
Command Modes
EXEC
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
Usage Guidelines
The show ip eigrp topology command can be used without any keywords or arguments. If this command is used without any keywords or arguments, then only routes that are feasible successors are displayed. The show ip eigrp topology command can be used to determine Diffusing Update Algorithm (DUAL) states and to debug possible DUAL problems.
Examples
The following is sample output from the show ip eigrp topology command:
Router# show ip eigrp topology
IP-EIGRP Topology Table for process 77
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
P 172.16.90.0 255.255.255.0, 2 successors, FD is 0
via 172.16.80.28 (46251776/46226176), Ethernet0
via 172.16.81.28 (46251776/46226176), Ethernet1
via 172.16.80.31 (46277376/46251776), Serial0
P 172.16.81.0 255.255.255.0, 1 successors, FD is 307200
via 172.16.81.28 (307200/281600), Ethernet1
via 172.16.80.28 (307200/281600), Ethernet0
via 172.16.80.31 (332800/307200), Serial0
Table 63 describes the significant fields shown in the display.
Table 63 show ip eigrp topology Field Descriptions
Field
|
Description
|
Codes
|
State of this topology table entry. Passive and Active refer to the EIGRP state with respect to this destination; Update, Query, and Reply refer to the type of packet that is being sent.
|
P - Passive
|
No EIGRP computations are being performed for this destination.
|
A - Active
|
EIGRP computations are being performed for this destination.
|
U - Update
|
Indicates that an update packet was sent to this destination.
|
Q - Query
|
Indicates that a query packet was sent to this destination.
|
R - Reply
|
Indicates that a reply packet was sent to this destination.
|
r - Reply status
|
Flag that is set after the software has sent a query and is waiting for a reply.
|
172.16.90.0
|
Destination IP network number.
|
255.255.255.0
|
Destination subnet mask.
|
successors
|
Number of successors. This number corresponds to the number of next hops in the IP routing table. If "successors" is capitalized, then the route or next hop is in a transition state.
|
FD
|
Feasible distance. The feasible distance is the best metric to reach the destination or the best metric that was known when the route went active. This value is used in the feasibility condition check. If the reported distance of the router (the metric after the slash) is less than the feasible distance, the feasibility condition is met and that path is a feasible successor. Once the software determines it has a feasible successor, it need not send a query for that destination.
|
replies
|
Number of replies that are still outstanding (have not been received) with respect to this destination. This information appears only when the destination is in Active state.
|
state
|
Exact EIGRP state that this destination is in. It can be the number 0, 1, 2, or 3. This information appears only when the destination is in the Active state.
|
via
|
IP address of the peer that told the software about this destination. The first n of these entries, where N is the number of successors, are the current successors. The remaining entries on the list are feasible successors.
|
(46251776/46226176)
|
The first number is the EIGRP metric that represents the cost to the destination. The second number is the EIGRP metric that this peer advertised.
|
Ethernet0
|
Interface from which this information was learned.
|
Serial0
|
Interface from which this information was learned.
|
show ip eigrp traffic
To display the number of Enhanced Interior Gateway Routing Protocol (EIGRP) packets sent and received, use the show ip eigrp traffic command in EXEC mode.
show ip eigrp traffic [autonomous-system-number]
Syntax Description
autonomous-system-number
|
(Optional) Autonomous system number.
|
Command Modes
EXEC
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
Examples
The following is sample output from the show ip eigrp traffic command:
Router# show ip eigrp traffic
IP-EIGRP Traffic Statistics for process 77
Hellos sent/received: 218/205
Updates sent/received: 7/23
Queries sent/received: 2/0
Replies sent/received: 0/2
Acks sent/received: 21/14
Table 64 describes the fields that might be shown in the display.
Table 64 show ip eigrp traffic Field Descriptions
Field
|
Description
|
process 77
|
Autonomous system number specified in the ip router command.
|
Hellos sent/received
|
Number of hello packets that were sent and received.
|
Updates sent/received
|
Number of update packets that were sent and received.
|
Queries sent/received
|
Number of query packets that were sent and received.
|
Replies sent/received
|
Number of reply packets that were sent and received.
|
Acks sent/received
|
Number of acknowledgment packets that were sent and received.
|
timers active-time
To adjust routing wait time, use the timers active-time command in router configuration mode. To disable this function, use the no form of the command.
timers active-time [time-limit | disabled]
no timers active-time
Syntax Description
time-limit
|
EIGRP active-time limit (in minutes). The time range is from 1to 4294967295 minutes.
|
disabled
|
Disables the timers and permits the routing wait time to remain active indefinitely.
|
Defaults
This command is disabled by default.
Command Modes
Router configuration
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
Usage Guidelines
In EIGRP, there are timers that control the time the router waits (after sending a query) before declaring the route stuck in active (SIA).
Examples
In the following example, the routing wait time is 200 minutes on the specified route:
In the following example, the routing wait time is indefinite on the specified route:
timers active-time disabled
Related Commands
Command
|
Description
|
show ip eigrp topology
|
Displays the EIGRP topology table.
|
traffic-share
To control how traffic is distributed among routes when there are multiple routes for the same destination network that have different costs, use the traffic-share command in router configuration mode. To disable this function, use the no form of the command.
traffic-share {balanced | min}
no traffic-share {balanced | min}
Syntax Description
balanced
|
Distributes traffic proportionately to the ratios of the metrics.
|
min
|
Uses routes that have minimum costs.
|
Defaults
Traffic is distributed proportionately to the ratios of the metrics.
Command Modes
Router configuration
Command History
Release
|
Modification
|
10.0
|
This command was introduced.
|
Usage Guidelines
This command applies to IGRP and EIGRP routing protocols only. With the default setting, routes that have higher metrics represent less-preferable routes and get less traffic. Configuring the traffic-share min command causes the Cisco IOS software to only divide traffic among the routes with the best metric. Other routes will remain in the routing table, but will receive no traffic.
Examples
In the following example, only routes of minimum cost will be used:
Related Commands
Command
|
Description
|
variance (EIGRP)
|
Controls load balancing in an EIGRP and IGRP internetwork.
|
variance (EIGRP)
To control load balancing in an Enhanced Interior Gateway Routing Protocol (EIGRP)-based internetwork, use the variance command in router configuration mode. To reset the variance to the default value, use the no form of this command.
variance multiplier
no variance
Syntax Description
multiplier
|
Metric value used for load balancing. It can be a value from 1 to 128. The default is 1, which means equal-cost load balancing.
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Defaults
1 (equal-cost load balancing)
Command Modes
Router configuration
Command History
Release
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Modification
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10.0
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This command was introduced.
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Usage Guidelines
Setting a variance value lets the Cisco IOS software determine the feasibility of a potential route. A route is feasible if the next router in the path is closer to the destination than the current router and if the metric for the entire path is within the variance. Only paths that are feasible can be used for load balancing and included in the routing table.
If the following two conditions are met, the route is deemed feasible and can be added to the routing table:
•
The local best metric must be greater than the metric learned from the next router.
•
The multiplier times the local best metric for the destination must be greater than or equal to the metric through the next router.
Examples
The following example sets a variance value of 4: