Follow the commands below to set a port to a fixed speed and duplex (autonegotiate off).
RT01#conf t
Enter configuration commands, one per line. End with CNTL/Z.
RT01(config)#
RT01(config)#interface FastEthernet4
RT01(config-if)#speed 100
RT01(config-if)#duplex full
RT01(config-if)#exit
RT01(config)#exit
RT01#
Supported autonegotiate off speed settings
– 10
– 100
Supported autonegotiate off duplex settings
– half
– full
Follow the commands below to set an interface back to autonegotiate on.
RT01#conf t
Enter configuration commands, one per line. End with CNTL/Z.
RT01(config)#
RT01(config)#interface FastEthernet4
RT01(config-if)#speed auto
RT01(config-if)#duplex auto
RT01(config-if)#exit
RT01(config)#exit
RT01#