network link goes down when moving sfp+ cable from one switch to another (identical settings)

[epicurean]

I migrated all my network connections from a brocade icx7250 to another identical one with exactly the same vlan settings. When I move the sfp+ cable from one of my nodes to the new switch, the network line goes down. I put the sfp+ cable back to the old switch and the link came back on. Both switches have the same firmware, same vlan configurations, POE settings etc.
I am at a loss on how to fix this. The reason for the change to the new switch is I managed to change to quieter newers fans for the newer switch.

 

[fireon]

I assume you are using DAC? Sounds like there are compatibility issues here. Can you get a link with the Swtich using the cables with another device?

 

[epicurean]

Actually, I am using the same OM3 cable + brocade sfp+ connectors.
Yes, the same cable works fine with other devices for both switches

 

[fireon]

I had almost the same problem about a year ago. For some reason (we still don't know why), the cable was a little too long. The link could not be established for this one connection only. A shorter cable then worked. Can you perhaps test this too?

 

[sw-omit]

One possible explanation IF it is caused by the cable could be hairline fracture of sorts that, when is put in the position on the first switch gets compressed/stretched together properly, and stretched/compressed out too much in the other.
For that a silly thought, if you swap the ends of the cable (so what goes in the switch and in the server) does it still work in the old switch and no longer in the new switch?

Or at least that's something that I've had happen with a dac before, swapping it around, which of course shouldn't matter, did matter, providing it was something within the cable itself so we replaced it.

 

[epicurean]

I didnt know an OM3 cable can be so sensitive. I will try the suggestions and revert with my results
Thank you

 

[epicurean]

I changed the connectors ( another pair of brocade ), same OM3 cable, and link is back up.
SO either 1 or both of the previous connectors is the culprit