Interface ManagementWhen the fast Ethernet interface is set to duplex negotiation, its remote end mustwork in the same mode. If this could not be achieved, then use forced setting toensure consistency of the working mode.The execution of speed negotiation after executing duplex full or duplex half at thefast Ethernet interface will restore the working mode to duplex negotiation. This willautomatically start the duplex auto process and negotiate the speed and the workingmode.For related commands, see speed, display interfaces.Example# Set the 100Base-T fast Ethernet interface to work in full duplex mode.[3Com-Ethernet0]duplex full2.1.2 loopback (Ethernet Interface)Syntaxloopbackundo loopbackViewEthernet interface viewParameterNoneDescriptionUsing the loopback command, you can enable the internal loopback and theexternal loopback on the Ethernet interface. Using the undo loopback command,you can disable the internal loopback and the external loopback on the Ethernetinterface.By default, the internal loopback and the external loopback are disabled on theEthernet interface.The internal loopback and the external loopback are enabled on the Ethernetinterface when some special functions are tested.13
