2940-TF problem using SFP port attached to 4503

Unanswered Question
Feb 16th, 2007

Has anyone seen this problem ? Any time my 2940 switches are reloaded, the gigabit SFP will not come back up, unless I do a shut, and no shut on the other end (4503). I do not see this on my 3750 switches. It only occurs on 4503 or 4506 switches. Both ends say they are connected, but pass no traffic until I bounce the 4500 side. I have tried various modes of port operation (nonnegotiate, trunk, dyn des, dyn, auto). Nothing seems to fix the problem. 4500 switches are running 12.2(25) SG and 12.2(31) SG.


I have this problem too.
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wallafly Fri, 02/16/2007 - 12:57

On the 4503 is it a 10/100/1000 port for sure? If it is, then set it to 1000 hard coded. It is having trouble negotiating the correct port speed probably.

rduke Sat, 02/17/2007 - 09:51

Sorry, I did not specify that I am using SX fiber SFPs, so it is 1000 only.

wallafly Sat, 02/17/2007 - 10:09

Let me tell you something that fixed my issue with the SFP on my 3560. This will sound ELEMENTRY...

press the SFP in different directions with some pressure and be patient....

THis fixed an sfp issue at my site and it was an uplink to a 4507.......

I put it on a forum like this and the next month someone responded that it was the ONLY fix and they just about went crazy!!!

rduke Sat, 02/17/2007 - 15:09

That might be the case if it were happening on just one, but I have a bunch of them doing this. Besides, the problem does not occur when I use 2940-3750 or 2940-2940 SFP connections. It only occurs on 2940-4500 switch connections. Also, this problem is easy to duplicate. I have a case open with TAC, but so far they have not come back with anything.


wallafly Sat, 02/17/2007 - 21:38

I understand you there then, I just saw the sfp and 4500 correlation and thought it made sense.


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