Symptom
1) 3850 port connected to a 6500 goes down after a reload because of UDLD err Disable on 6500 end
2) Both sides are configured for "udld aggressive" globally
Known issue with 1 Gig Uplink
1) 3850 connected to ss6k/3650 with 4x1 GIG Uplink module moves to rerr-disable followed by fed crash
2)Remove 1 GIG Uplink FRU after save/reload with udld global/port level config
Conditions
This issue is seen with UDLD and UDLD aggressive config
Workaround
Configure udld on the 3850 port explicitly (whether global config present or not doesn't matter) and configure err Disable recovery on 6500
Further Problem Description
1) shut/no shut on 6500 port does not help (link comes up following shut/no shut but falls back to err-Disable)
2) Only way to recover is to disable/enable udld on 3850 either globally or on the affected port
