Auto-Negotiation on Ethernet InterfacesBy default, auto-negotiation of speed and full duplex mode is enabled on 10/100/1000 Base-T Ethernet interfaces. Only 10GE interfaces donot support auto-negotiation.When using 10GE interfaces, verify that the 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, and auto-negotiation is the easiest way toaccomplish that, as long as the remote interface is capable of auto-negotiation.NOTE: As a best practice, Dell Networking recommends keeping auto-negotiation enabled. Only disable auto-negotiation onswitch ports that attach to devices not capable of supporting negotiation or where connectivity issues arise from interoperabilityissues.NOTE: If the interface does not come up when you configure 10/100/1000G speed, configure the interface speed using thespeed command manually on both the ends and disable autonegotiation if it is enabled.NOTE:Setting the Speed of Ethernet InterfacesTo discover whether the remote and local interface requires manual speed synchronization, and to manually synchronize them if necessary,use the following command sequence.1 Determine the local interface status. Refer to the following example.EXEC Privilege modeshow interfaces [interface | stack—unit stack-unit-number] status2 Determine the remote interface status.EXEC mode or EXEC Privilege mode[Use the command on the remote system that is equivalent to the first command.]3 Access CONFIGURATION mode.EXEC Privilege modeconfig4 Access the port.CONFIGURATION modeinterface interface-type5 Set the local port speed.INTERFACE modespeed {10 | 100 | 1000 | 10000 | auto}NOTE: If you use an active optical cable (AOC), you can convert the QSFP+ port to a 10 Gigabit SFP+ port or 1 GigabitSFP port. You can use the speed command to enable the required speed.6 Optionally, set full- or half-duplex.INTERFACE modeduplex {half | full}7 Disable auto-negotiation on the port.INTERFACE modeInterfaces 425
