I have Cisco switch 3750 it have strange problem with the SFP connector. It sayss in the logs that an error occurred which caused from link flap or fluctuation. the solution for this to take it out then install it in and do shut/no shut, but not all time will work. I read about this in Cisco they say the SFP it's not approved from Cisco. But I checked with the vendor as they say it is approved and the opened a tag cause with Cisco but they did not replayed yet I want to know some if did you Experts faced the same issue.
Our topology: we have 2 core 6513 catalyst then there are 1 SFP Connector uplink from each core connect to our edge switch 3750 sires Also to SFP connector.
We are using GLPB between the 2 core so I checked if the spanning-tree have to deal with it but all configuration seem to be ok
Also the OSI versions are updated and the fiber optic cable are single mode which I tested with a fluke it had 0 D.B to avoid this issue.
I did also some line command in the interface As UDLD switch it to aggressive mode and Error recovery cause, but still I have the link is down.
