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EIGRP Neighbor flapping 4500 & 6500

Thanks in advance for your help, I'm hoping that this is a known issue since it occurs on several of our 4500 access swiches with redundant sup V and port channel uplinks (routed) to 6500 (core) switches, two to three times a day we experience the loss of EIGRP adjacencies on these port channels, the adjacencies are re-form inmediately which causes EIGRP reconvergence, table updates etc. There is nothing special about this configuration, 4500 sup V active has two 1Gb ports bundled (L3) and uplinked to "core 1 port channel #1, 4500 sup V standby is a duplicate of the active sup with two 1Gb ports bundled (L3) uplinking to "core 2 port channel #1. Nothing seems to trigger the flap, it just seems to happen without any good reason. Any help is appreciated.


Re: EIGRP Neighbor flapping 4500 & 6500

Hello, Can you try removing the redundant port channell and keep only one port channel between the chassis. and see whether the problem

re occurs.



Community Member

Re: EIGRP Neighbor flapping 4500 & 6500

Did you ever get a response to this issue? I am finding the same problem, only with no port channels. A few times a week, all the neighbors of this 4509 will time out and send Peer Termination messages, and then almost instantly the neighbors are rediscovered and adjacencies are reestablished.


Re: EIGRP Neighbor flapping 4500 & 6500

What is the peer down reason in the log? Hold timer expired? Retry limit exceeded?

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