Error message in log: %PIM-5-NBRCHG: neighbor

mortonjes · ‎04-20-2009

I have a Cisco 7206 that has EIGRP configued as well as Multicast. Every once in a while I see this error in the log:

Apr 20 07:06:16.415 EDT: %PIM-5-NBRCHG: neighbor 10.0.0.1 DOWN on interface GigabitEthernet0/1 non DR

Apr 20 07:06:29.843 EDT: %PIM-5-NBRCHG: neighbor 10.0.0.1 UP on interface GigabitEthernet0/1

The network is a stub network and EIGRP really isn't needed so I added static routes but left EIGRP routing enabled.

Multicast isn't needed on this router either. The routers peer doesn't get this message.

I'm thinking this message is due to multicast but not sure exactly why.

I don't see any performance / application problems because of this and I see on Cisco that "No Action is required" for this error but I'd really like to know what might be causing it.

Any help would be greatly appreciated

Giuseppe Larosa · ‎04-20-2009

Hello Jesse,

these messages just tell that the PIM adjacency failed and then was created again.The reason is PIM hellos not received (or not processed see below for ignored(overruns).

this can happen for different reasons:

if the link is full in the direction towards the C7206 and the device on the other side has no implicit system queue for routing traffic there is a chance that PIM messages are lost, you may need to protect routing traffic including PIM creating a class for it in a CBWFQ applied outbound.

Another possible reason could be that there are ignored or overruns on interface gi0/1 that tells the other side is speaking too fast for the capabilities of the C7206 (that depends on the type of NPE installed but also with NPE-G1 and NPE-G2 doesn't support line rate on multiple GE ports)

However, if you don't need multicast on this router you can simply do the following:

int gi0/1

no ip pim sparse-mode

(or other type you have configured on it)

Hope to help

Giuseppe