CRC Errors

[ejrein]

Hello all

I have a situation that I am unable to understand. We have two Nexus 9K's connected across two different sites via two 10GB fiber links. Both ports are part of the same port-channel. However the other day we were getting log messages indicating that a different port (and on a different port-channel) on one of the 9K's was dropping. TAC looked at it and determined that one of the 10GB links to the other 9K was accumulating a bunch of CRC errors. We shut the port down and we did not receive anymore errors. My question is how can CRC errors on one physical port (and on a port-channel) can impact another physical port (and on a different port-channel) on the same switch?

Thanks!

[Leo Laohoo]

CRC errors always means it's a layer 1 issue. The link could be faulty or degrading. Better get someone to check the link to make sure.

[ejrein]

We actually replaced the two SFP's and the fiber cables connecting to both switches and also moved them to another interface and received the same results. The odd thing is this is affecting a completely different physical port that is on another port-channel. I have never seen this kind of behavior before. Another tech suggested it is caused by cut-through switching but I still don't understand how it affects a different switch port.

[Leo Laohoo]

Could be a code bug.