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New Member

Overrun errors on port-channel interfaces?

I've got a couple of 6509's running 12.1(19), attached to various 35xx switches using L2 LACP port-channels. Everything works just fine, but when looking at the port-channel stats, it occasionally shows huge numbers of overrun errors, which clear up within a couple of seconds.

We've tried the same configuration using PaGP, with the same result. Other than the inexplicable overrun counter, which makes me suspect that some part of the matrix is confused over whether the port-channel is L2 or L3, there are no performance problems, and ports move in and out of the bundle as expected.

This only happens on my 65xx-to-35xx connections, not on any other combination.


Re: Overrun errors on port-channel interfaces?

New Member

Re: Overrun errors on port-channel interfaces?

What type of modules are you using with your port-channel interfaces? It's likely a blocking card that uses a shared buffer with the other interfaces on the card, so you may be experiencing spikes in traffic on your other interfaces which gives you overruns on the links in your etherchannel bundle.