WS-C2960X-48FPD-L SFP GLC-SX-MM issues

[hi.sadiki]

Hello Guys,

Last saturday we changed an old user access (3560) in its end of life by  new a WS-C2960X-48FPD-L 15.2(2)E5.

We connected the new user switch 2960X by the GLC-SX-MM that we removed from the old switch to the distribution

Surprise !!  

One's the GLC-SX-MM  put inside the 2960X the port didn't come up

I perfomed sh int status and sh inventory, then I saw that the GLC-SX-MM  is regognised as  SFP-10GBase-LR in the 2960X.

I was lucky, My collegue  had a Spare GLC-SX-MM, we triyed it, and it worked like a charm.

My questions is :

Why with  two GLC-SX-MM, one works  and the other did not as it showed  SFP-10GBase-LR instead of 1000baseSX?

Why the GLC-SX-MM that worked in the 3560 as 1000baseSX  didn't work on the 2960X and was seen as SFP-10GBase-LR ?

I am attaching two picture of the SFPs GLC-SX-MM. the one that I had on 3650 (not working) and the other which worked if somebody can see any  difference.

Thanks for your help

[Leo Laohoo]

The "non working" one is a FAKE.  

The serial number of the SFP is something I've never seen before.

If they are indeed fake, Cisco would like to talk to you.  Not because you purchased a fake module, rather, they want to know from WHOM did you purchase the counterfeit items from. 

[hi.sadiki]

Hello,

Thanks for answering me.

What shall I do to check if they are fake please ?

[Leo Laohoo]

Someone is going to contact you.

[Monica Lluis]

We are looking into this.