Interface Commands4-1334Default Setting• Auto-negotiation is enabled by default.• When auto-negotiation is disabled, the default speed-duplex setting is 100halffor 100BASE-TX ports and 1000full for Gigabit Ethernet ports.Command ModeInterface Configuration (Ethernet, Port Channel)Command Usage• To force operation to the speed and duplex mode specified in a speed-duplexcommand, use the no negotiation command to disable auto-negotiation onthe selected interface.• When using the negotiation command to enable auto-negotiation, theoptimal settings will be determined by the capabilities command. To set thespeed/duplex mode under auto-negotiation, the required mode must bespecified in the capabilities list for an interface.ExampleThe following example configures port 5 to 100 Mbps, half-duplex operation.Related Commandsnegotiation (4-133)capabilities (4-134)negotiationThis command enables autonegotiation for a given interface. Use the no form todisable autonegotiation.Syntax[no] negotiationDefault SettingEnabledCommand ModeInterface Configuration (Ethernet, Port Channel)Command Usage• When auto-negotiation is enabled the switch will negotiate the best settingsfor a link based on the capabilities command. When auto-negotiation isdisabled, you must manually specify the link attributes with the speed-duplexand flowcontrol commands.Console(config)#interface ethernet 1/5Console(config-if)#speed-duplex 100halfConsole(config-if)#no negotiationConsole(config-if)#
