Cisco 2960L 1000BaseSX SFPs sometimes work

[mnorvalls]

Hello,

I have been dealing with a Cisco 2960L-16TS-LL that has two Cisco branded GLC-SX-MMD SFPs installed. Both SFPs show up with all of their information when using the "show inventory" command. Both ports are set up as an etherchannel with LACP and are connected to another device that gets turned off and on frequently. I am having an issue where sometimes the SFP ports will work fine and everything is happy, but other times either one or both SFPs will not go active.

The solution so far has been to disconnect and reconnect the TX fiber line, and then all is happy again. 

Does anyone have any ideas as to what could be causing this?

Thanks for your time

[Reza Sharifi]

Hi,

If you have spare optics and cables, try replacing the cable first and then the SFP and test again.

HTH

[mnorvalls]

Hello Reza,

I have three of these sytems with the same setup, and all encounter the same issue even when using spare SFPs and cables

[Mark Malone]

are they all running same IOS software and same hardware, maybe changing IOS on one of them see if that sorts it

[shaps]

Are all the SFPs/cables you have used in the same port, if so it may be an issue on the port itself

[mnorvalls]

@shaps  Well it happens on either of the two module ports on any of the three switches. And it seems to be random as to which port will not become active on any given power-up.

[mnorvalls]

@Mark Malone  Yes they are, I will try that later today or tomorrow Thanks

[mnorvalls]

Tried the most up to date IOS today and still am getting the same issues