C5-Series, firmware 6.42.10.0016 through 6.61.07.0010
C5Kxxx-xx(P2) (2 SFP+ slots for 10GB-xx-SFPP or MGBIC-xxxx)
B5-Series, firmware 6.42.10.0016 through 6.61.07.0010
B5Kxxx-xx(P2) (2 SFP+ slots for 10GB-xx-SFPP or MGBIC-xxxx)
Used the 'clear port advertise <port#> pause' command to disable pause/flowcontrol advertisement on a "SFP+"-labeled port with installed 1Gb MGBIC-xxxx (9852).
A brief cycle of port link state is expected upon issuing this command.
Ethernet link is lost on the SFP+ port, and does not return.
Upgrade to firmware 6.61.08.0013 or higher (14480).
Release notes state, in the 'Changes and Enhancements in 6.61.08.0013' section:
Corrected an issue where "clear port advertise pause" would disable a 10Gb (tg) port.
After the problem has occurred; recovery requires re-enabling pause advertisement for affected ports, then resetting the switch.
Rather than port-disabling pause advertisement on a SFP+ port, globally disable flowcontrol ('set flowcontrol disable') on the switch.