We have two switches connected via fibre. Both ends appear to be up and the config is correct. Port is tagged on the correct VLANs both sides.
Looking at the counters on the interface I can see broadcast traffic but no unicast traffic. Also doing a "show mac-address" doesn't show an mac-addresses on the port. Switches have been working fine for 6 months and no config change from what I can tell.
Assuming possible SFP fault or fibre patch is damaged. Any other troubleshooting steps to diagnose?