Symbol Error Frames

[sschulz]

We have 4 switches connected and we had issues with users connecting from the furthest switch. After investigation, I found that there were huge numbers of Input errors on one switch. I swapped the fibre cable and this improved performance but the Input error count is still going up.

This is a rough idea of what we have:

Cisco 3750G connected to Cisco 3550-12G connected to 3750-48 (using Singlemode Fibre), connected to 3750-48 (using Multimode Fibre). The errors occur on the 3750-48 connecting to the 3750-48 and also the 3550-12G. Errors are shown on the interface. I am using LX LC connectors for this connection. Can anyone help?

[Prashanth Krishnappa]

Symbol-Err are seen when the Mac sees "invalid" symbols. In most cases, this is a physical problem - Gbics, fiber, etc. You might want to try replacing GBICs

[Richard Burts · Accepted solution]

I recently had an experience at a customer site where we were getting symbol errors. We tried various combinations of replacing GBICs, fiber patch cables, etc. Eventually we got the provider involved in troubleshooting the issue. They found a problem in the fiber in their network and fixed it.

I agree for this problem look closely for some physical layer problem.

HTH

Rick

[sschulz]

Thanks for the information. I replaced the GBIC on the other end of the switch showing the Symbol error frames and this resolved the issue I had.