Swapping fibres in VSP SMLT to EXOS LAG = SMLT port down

[dabbler]

I have 2 VSPs, VSP1 and VSP2 that have SMLT fibre connections to EXOS switch stacks that use sharing.

I built a new EXOS switch stack to replace an existing one, created a new SMLT and all that worked fine. I then disconnected both fibres from the existing EXOS stack and connected both fibres from the new EXOS stack as I need to use the existing VSP SMLT ports.

The fibre on VSP2 works and provides connectivity but the fibre port on VSP1 is now down. Changing fibre cables, SFPs, rebooting the EXOS and VSP did not help.

Anyone know why moving both fibres on an SMLT connection to a new switch stack would cause this?

[dabbler]

There is no light at all being transmitted from the VSP port on either core, so swapping the tx/rx round won't be of help at this point. I tried swapping the fibres round on the 2 ports on the EXOS switch stack but the fault stayed with the port, indicating the fibre cables are ok.

[RobertD1]

If you disable the working leg does it start to work then? Have seen this when same port goes to wrong stack. Otherwise, I suggest you raise a case.

[dabbler]

I tried pulling the working fibre, but no difference.

However, running "show pluggable detail" on the VSPs and looking at the SFP type showed "10GbSR". The EXOS stack command "show port transceiver information detail" showed a "SF+LRM". It turned out that whoever built the original EXOS stack did not use our standard short-haul SFPs, they used 1 short haul and one long haul at each end.
I swapped the long haul SFPs out for the standard short hauls and the fibres burst into life.
I should have seen that when checking the rx/tx power earlier.

Thanks a lot for all your help Robert, I appreciate it very much.

[RobertD1]

Glad you got it sorted in the end.