Cisco 3750 + SFP Module Disabled?

Hi all,

I've plugged a new SFP 1000Base-T SFP module in a port on a 3750 switch, however there is no connectivity. I've connected laptop directly to the module but still no joy.

The switch is managed by a third party who have previously said that everything 'looked ok to them' but I'm not convinced.

Are the any well known issues that can cause this behaviour?

Thanks.

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Comments

dtlokee

Yes, some 3rd party GBICs will cause the interface to go into err-disable state, there was a command like "service invalid-gbic" or somthing like that I had to use once to make them work. You could also turn off errdisable invalid-gbic.

I am not sure if this is what your issue is but I ran into something like this in the past

zoidberg

service unsupported-transceiver

hopefully that should do the trick for you

mattrgee

Hi,

Thanks for the replies, the company that manage our switches resolved this today, but I managed to get an explanation from them as to why it wasn't working.

"The SFP module was working alright. Couple of ports were put in err-disable state as some sort of looping and duplicate addresses were found on those ports . I have activated them now. The port gi2/0/12 was connected somewhere 2 days ago ( im assuming here ) causing the looping and the other ports gi1/0/8 and gi2/0/8 to be put in err-disable state. Now the issue is resolved."

I had originally moved an SFP module from gi2/0/12 to gi1/0/8 then gi2/0/8 when trying to troubleshoot the problem. Moving the SFP module appears to have placed the port in an err-disable state. If someone could explain why this is I'd be interested to hear. Port Security isn't enabled.

Thanks

mattrgee

Actually, bpduguard is enabled on all ports.

Say a switch connected to a SFP module that was plugged into a port with BPDU guard enabled, the port would go into err-disable state.

If that SFP module is then moved to another port without a switch connected, I wonder whether the mac address of the SFP module causes the next port to go into err-disable state as well? This would mean that the switch knows the mac addresses of SFP modules that have previously caused an err-disable state?

Just an idea???

laidbackfreak

mattrgee wrote: »

I wonder whether the mac address of the SFP module

I didnt think the SFP module had its own mac address ??

mattrgee

You might be right there.

Would like to get to the bottom of this really.