Env: Cisco Nexus 9508 with an 10Gbase-LR SFP connecting to the carrier. For the last few days the interface has been racking up input errors and CRC. Hundreds ever few seconds. We've replaced the SFP and we replaced the fiber from the SFP to the patch panel.
What trouble-shooting methods do I have my disposal once the carrier gets on site? I've had these maddening all night affairs where the vendor says "we're all clean to our next device in Deluth (or wherever). Besides replacing optics, shutting/no shutting the interface, what other tools would help to isolate the cause of these errors? Thank you.
(BTW A tech at the data center tried to throw us a loop but the interface went down from UDLD. If there's a way to make a hard loop to us more informative that would be good to know too)