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New Member

3560 Fiber

PLEASE HELP. We are trying to connect a Supervisor IV [Cat4506] via 2 GBICs to two SFPs in a 3560G. No matter what we try, the links on the 3560 do NOT stay up!! Has anyone seen anything like this? THANKS!!!

New Member

Re: 3560 Fiber

Have you tried the speed nonegotiate on the supIV?

Check to see weather errdisable is causing the ports to lose connection too

Need more information about what the ports errors look like!


Re: 3560 Fiber

Are they all the same speed and distance type?

Fiber interfaces don't "auto-negotiate" ... they are a fixed speed. If you have 100M talking to Gig, they'll never connect.

Likewise if you are trying to use SX and LX or ZX

What specific hardware are you trying to use (GBICS aned SFPs)?

Good Luck


New Member

Re: 3560 Fiber


We did try the non-negotiate option with speed. No luck, We ARE however, trying to connect SX on both sides. the GBIC -5484 are on the 4500 and the LC connectors are the ones chosen for the SFP side [3560] ..

Any other ideas?

Re: 3560 Fiber


How far are these switches ?? If they are on the same rack, can u connect the switches with a cross cable and do some basic configs to get the trunk UP ? If this works, we can look more on the fiber hardware (port or SFP etc) , than the config !!!!


New Member

Re: 3560 Fiber

Hi Raj.

That's how we got around it ... crossover cable. BUT trunking not working. The next step will be to get the trunking working - we think it's a VTP issue... BUT once working, we're going to attack the fiber and I am going to put the configs up. Thanks Raj!!!