EIGRP Adjacencies

boostinbadger

I have configured EIGRP across three routers, but R1 keeps finding the adjacency through DUAL then 3 minutes later it goes down and says that the retry has been exceeded.

Here is a readout:

R1_1760#
*Apr 5 03:22:41.416: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 172.12.123.3 (Serial0/0) is up: new adjacency
R1_1760#
*Apr 5 03:25:45.938: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 172.12.123.3 (Serial0/0) is down: retry limit exceeded
R1_1760#
*Apr 5 03:26:25.186: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 172.12.123.3 (Serial0/0) is up: new adjacency
R1_1760#
*Apr 5 03:29:29.713: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 172.12.123.3 (Serial0/0) is down: retry limit exceeded
R1_1760#
*Apr 5 03:30:05.964: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 172.12.123.3 (Serial0/0) is up: new adjacency


What would cause this?

Netwurk

There's a Ciscopress chapter on troubleshooting EIGRP that Cisco is currently posting for free as a sample from one of their books

Should tell you everything you need to troubleshoot

Troubleshooting EIGRP > Troubleshooting EIGRP Neighbor Relationships

My own advice would be to make sure your serial cables are good and that they are secured to your interfaces

Also make sure that your routers are advertising the correct IPs

The show ip eigrp neighbors command should be able to help you investigate. Try it on both ends of the connection.

boostinbadger

I figured it out. Just some stray RIP configs I forgot to take out from previous labs. Should have checked there first.