Enabling remote fault notification

RFN configures the transmit port to notify the remote port whenever the fiber cable is either physically disconnected or has failed.

RFN is enabled (set to auto-gig option) by default.
  1. Enter interface configuration mode to enable RFN on a particular interface.
    device(config)# interface ethernet 1/1/1
  2. Re-enable RFN if it was disabled using the neg-off option.
    device(config-if-e1000-1/1/1)# gig-default auto-gig
    To disable RFN, use the gig-default neg-off command.