Cisco Systems 78-11741-02 Disabling Route Summarization, Goodbye Message, IPC-262, Value mismatch

Configuring EIGRP

EIGRP Configuration Task List

•The K-value mismatch error message can also be displayed if one of the two peers has transmitted a “goodbye” message, and the receiving router does not support this message. In this case, the receiving router will interpret this message as a K-value mismatch.

The Goodbye Message

The goodbye message is a feature designed to improve EIGRP network convergence. The goodbye message is broadcast when an EIGRP routing process is shutdown to inform adjacent peers about the impending topology change. This feature allows supporting EIGRP peers to synchronize and recalculate neighbor relationships more efficiently than would occur if the peers discovered the topology change after the hold timer expired.

The goodbye message is supported in Cisco IOS Release 12.3(2), 12.3(3)B, and 12.3(2)T and later releases. The following message is displayed by routers that run a supported release when a goodbye message is received:

*Apr 26 13:48:42.523: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 10.1.1.1 (Ethernet0/0) is down: Interface Goodbye received

A Cisco router that runs a software release that does not support the goodbye message can misinterpret the message as a K-value mismatch and display the following message:

*Apr 26 13:48:41.811:	%DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor	10.1.1.1
(Ethernet0/0) is down:	K-value mismatch

Note The receipt of a goodbye message by a nonsupporting peer does not disrupt normal network operation. The nonsupporting peer will terminate session when the hold timer expires. The sending and receiving routers will reconverge normally after the sender reloads.

Applying Offsets to Routing Metrics

An offset list is the mechanism for increasing incoming and outgoing metrics to routes learned via EIGRP. An offset list provides a local mechanism for increasing the value of routing metrics. Optionally, you can limit the offset list with either an access list or an interface. To increase the value of routing metrics, use the following command in router configuration mode:

Command	Purpose
Router(config-router)# offset-list[access-list-number	Applies an offset to routing metrics.
access-list-name] {in out} offset [interface-type
interface-number]

Disabling Route Summarization

You can configure EIGRP to perform automatic summarization of subnet routes into network-level routes. For example, you can configure subnet 131.108.1.0 to be advertised as 131.108.0.0 over interfaces that have subnets of 192.31.7.0 configured. Automatic summarization is performed when there are two or more network router configuration commands configured for the EIGRP process. By default, this feature is enabled.

To disable automatic summarization, use the following command in router configuration mode:

Cisco IOS IP Configuration Guide

IPC-262