Looking for some assitance here, as I have an issue that's driving me nuts.
We have a campus network with a 4506 as the core with OM3 fibre links to dual distribution switches (one on the 4th floor of each wing, and one on the ground floor).
The distribution switches are Catalyst 3750G-12S-E, using 1000BaseT Copper Modules. From each distribution location we have Cat6a copper links to each floor.
Each floor has it's own wiring cabinet with 2 x 3560-48PS-S access switches. Each access switch is dual homed to the ground floor distribution and 4th floor distribution switches.
The problem is the physical link status of the SFP modules, primarily the ones in the 3750G. When the distribution switches are rebooted, we only get link back on about 30%-40% of the links.
I have swapped GBIC's (SFP's) between switches, tried 1000-Full configuration to disable auto-negitiation, tried mdix-auto on/off (one end and both ends), straight through cables and crossover cables. Also the patch cables we are using are Systimax 10G.
There seems to be no ryhme or reason to which links will fail, and if you remove the GBIC and back to back them in a standalone switch, they work, just not in the 3750G's.
There are 8 3750G's and we have purchased over 160 SFP modules. This is not an STP issue, as the link never gets up/up and in some cases, we see no GBIC inserted ion the 3750G interface.
I can't beleive we have multiple failed SFP modules.
Any help would be appreciated, sorry for the long winded post!