speed auto duplex auto Ensure the SFP matches the port type:

interface GigabitEthernet0/1 speed 100 duplex full Or use auto-negotiation (recommended for most modern networks):

Command Failed Port Not Compatible Duplex Mode Apr 2026

speed auto duplex auto Ensure the SFP matches the port type:

interface GigabitEthernet0/1 speed 100 duplex full Or use auto-negotiation (recommended for most modern networks): command failed port not compatible duplex mode