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New Member

SFP overheating


I have a 3750G-12S with SFP modules GLC-GE-100FX=.

Interfaces work fine, but I noted an unusual overheating of SFP modules.

I don't know the exact temperature, but to give you an idea, when I remove an SFP module from the slot I difficultly can take it in my hand.

Did anybody have a similar experience?

Cisco Employee

Re: SFP overheating

Did you get any alarms or logs on the switch. Check the " show log ".

This could be due to a bad GBIC. I have come across a few cases where overheating causes tha GBIC failure. Though the GBIC is working and it might fail in near future if it crosses the threshold.

Contact TAC for the same.

-amit singh

New Member

Re: SFP overheating

I didn't get any alarms or logs, and I can exclude a bad module because I have the same experience on several interfaces.


New Member

Re: SFP overheating


Yes, I have been experiencing this problem, and I have the (un)official workaround from cisco TAC. I have also a bug ID CSCsj01656  for this, but I cant see any details from this bug, because it declared "proprietary" in bugtoolkit.

The workaround is to leave a blank hole between sfp:s, in other words put sfp only other place in -12S switch. (this makes this switch -6S when operating in 100M mode). This applies only to GLC-GE-100FX sfp:s with 3750-12S switch.