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4908/3500 problem

I've got a 4908 acting a an L2 switch (don't ask me why, I inherited it that way). It has 5 5484's in it, which each attach to a 3548 in an IDF. I have two 3500's in it, each attaching via the 50cm cable to a 3508. The problem is I'm losing the connectivity via the 3500's. I upgraded the flash today, so that's current. Everything works fine after rebooting, but about a half hour later, the 3500's drop out again, even though I have green lights everywhere.

sh cdp neighbors

will not show the 3508's attached via int gig1 and gig2 even though

sh int

reports int gig 1 & 2 as being up up. I've changed out the 3500's, and moved them around in the 4908 so neither the gig port nor the gig stack module is the problem, any ideas?????


Cisco Employee

Re: 4908/3500 problem

Really not much info to work with, but I would make sure the 4908 is the root of the Spanning-tree. In addition, I would make sure the 4908 is running the latest software.

At the time of the problem, locate 2 hosts that cannot communicate through the 4908. Verify mac entries using the 'show bridge' command on the 4908 and the 'show mac dyn' command on the 3500s. Try to trace out where MAC addresses may be missing. Use the show interface command to check for raw counters and note any missing packets.

On the 4908G-L3, issue the commands show epc status and show epc counters to verify no bad hardware.