Interfaces | 455Auto-Negotiation on Ethernet InterfacesSetting speed and duplex mode of Ethernet InterfacesBy default, auto-negotiation of speed and duplex mode is enabled on 10/100/1000 Base-T Ethernetinterfaces. Only 10GE interfaces do not support auto-negotiation. When using 10GE interfaces, verify thatthe settings on the connecting devices are set to no auto-negotiation.The local interface and the directly connected remote interface must have the same setting, andauto-negotiation is the easiest way to accomplish that, as long as the remote interface is capable ofauto-negotiation.Note: As a best practice, Dell Force10 recommends keeping auto-negotiation enabled. Auto-negotiationshould only be disabled on switch ports that attach to devices not capable of supporting negotiation orwhere connectivity issues arise from interoperability issues.For 10/100/1000 Ethernet interfaces, the negotiation auto command is tied to the speed command.Auto-negotiation is always enabled when the speed command is set to 1000 or auto.To discover whether the remote and local interface require manual speed synchronization, and to manuallysynchronize them if necessary, use the following command sequence (see Figure 20-35 on page 456):Note: Starting with FTOS 7.8.1.0, when a copper SFP2 module with catalog number GP-SFP2-1T is usedin the S25P model of the S-Series, its speed can be manually set with the speed command. When thespeed is set to 10 or 100 Mbps, the duplex command can also be executed.Step Task Command Syntax Command Mode1 Determine the local interface status. SeeFigure 20-34.show interfaces [interface | linecardslot-number] statusEXEC Privilege2 Determine the remote interface status. [Use the command on the remote systemthat is equivalent to the above command.]EXECEXEC Privilege3 Access CONFIGURATION mode. config EXEC Privilege4 Access the port. interface interface slot/port CONFIGURATION5 Set the local port speed. speed {10 | 100 | 1000 | auto} INTERFACE6 Optionally, set full- or half-duplex. duplex {half | full} INTERFACE7 Disable auto-negotiation on the port. If thespeed was set to 1000, auto-negotiationdoes not need to be disabled.no negotiation auto INTERFACE8 Verify configuration changes. show config INTERFACE
