Switch ports have incorrect polarity

dharvison · ‎04-01-2002

If I connect a lan analyzer to one of the ports on one of my 3524s, it indicates that there there is a polarity mismatch. I am using a known good patch cable and other ports do not cause this. Does anyone know what could cause this? Is the switch port defective?

timstewart · ‎04-01-2002

You could be potentially running into a problem with a small batch of 3524's. This batch of switches had a problem where the polarity was reveresed on pins 1-2 and 3-6. This typically does not cause any problems since most NIC cards support autosense polarity correction. NIC card's manufactured prior to 1990 usually do not support this. If you believe this is the issue, then please open a case with the TAC at which point they can determine if your switch(s) are part of this batch, and if so they will replace them.

dharvison · ‎04-01-2002

Thank you Tim. This problem would affect some ports on a switch but not all of them?

timstewart · ‎04-01-2002

Yes, the odd numbered ports are the only ports effected by this (ports 1, 3, 5, etc.).

dharvison · ‎04-01-2002

You are correct. It is an odd port on both switches that exhibit this. Thank you very much.