1GB SFP in SFP+ Slot Problems

[Mike Wagner]

Hi All,

We have an 8 port 3560CX with 2 SFP+ ports.  It's replacing an older 3560.  The old 3560 had a third party SFP that connected back to the hub site of our fiber provider.  That same SFP will not work in the SFP+ slots of the new switch.  I've even tried entering the commands to allow unsupported transceivers.  So, I went ahead and bought a genuine Cisco SFP, and it still will not work.  The light for the port turns green, but the port does not come up at all.  Nothing in the logs mentioning any issues with the port.

We're going to try hard-coding each end to 1000/full.  Do you have any suggestions for other things to try if that doesn't work?   A regular SFP should work in an SFP+ slot, correct?

Thanks,

-Mike

[Reza Sharifi]

Hi,

The 3560CX comes with 2 SFP slots and not SFP+.

They only support 1Gig and not 10Gig.

Can you try crossing the fiber strands on one side of the connection and test again?

HTH

[Mike Wagner]

Hi Reza,

Thank you for responding.  These are indeed SFP+ slots.  I purposely bought the switches for that for future use, and verified they are indeed SFP+

The fiber strands have remained the same placement, as we didn't switch the fiber cable in the patch panel.  

Thanks,

Mike

[lpassmore]

Maybe post the exact model of the switch (Show version) and also the part number of the Cisco SFP module that you are trying.

Also check the compatibility matrix (http://www.cisco.com/c/en/us/td/docs/interfaces_modules/transceiver_modules/compatibility/matrix/GE_Tx_Matrix.html)

If the SFP is in the compatibility matrix then it should work and if it doesn't with settings set to auto (not fixed) then I would recheck the cabling.  

Do the green lights appear on the far end switch also?

Is there anything in the logs when the module is inserted?
Do a show int status command