Eigrp error message with interface down

[mcardell]

Good morning,

I got the following EIGRP error message:

Aug 10 06:10:29: %DUAL-5-NBRCHANGE: IP-EIGRP 72: Neighbor 10.20.10.3 (Serial0/0.1) is down: interface down

But I have no visibility about any change on the interface. On the router the interface is still up and no up/down message is reported. How can the EIGRP have seen the interface down if the interface has been up all the time?

Is it only from the routing point of view?

Matteo

[amit-singh]

Hi Matt,

This msg means that EIGRP has lost its neighbor relationship with Neighbor 10.20.10.3.Now tell me is that a point-point connected link to Neighbor 10.20.10.3 or how it is econnected.

This message means that a hello hasnot been seen from the neighbor and after the routerdead interval that is hold time interval its is clearing the neighbor relation ship with that router.

Do " show IP eigrp neighbor " and see if you list that neighbor in the neighbor table.

There could be a few resons for that :

1. The interface has gone down that is connected to this router but its not the case here,

2. It could be due to the congestion on the link the transmitted hellos are not send or recieved.

HTH,

-amit singh

[ruwhite]

It can't be #2, because the message would then read: "hold timer expired..." I'll bet the interface went down and came back up without the attendant interface down/up messages, or EIGRP thought the interface was down because the routing table reported it down, but it wasn't down at layer 2.

I assume this isn't reproducable, or otherwise I'd turn on debug ip eigrp notifications to see if the routing table is actually telling eigrp the interface is down, or if eigrp is assuming the interface is down on its own. Don't leave debugs on in a production network, just to try and catch this, though....

:-)

Russ.W