Cisco Systems 3750E Setting the Interface Speed and Duplex Parameters, Speed 10 100 1000 auto 10

Chapter 11 Configuring Interface Characteristics

Configuring Ethernet Interfaces

•If one interface supports autonegotiation and the other end does not, configure duplex and speed on both interfaces; do not use the auto setting on the supported side.

•When STP is enabled and a port is reconfigured, the switch can take up to 30 seconds to check for loops. The port LED is amber while STP reconfigures.

Caution Changing the interface speed and duplex mode configuration might shut down and re-enable the interface during the reconfiguration.

Setting the Interface Speed and Duplex Parameters

Beginning in privileged EXEC mode, follow these steps to set the speed and duplex mode for a physical interface:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface interface-id	Specify the physical interface to be configured, and enter interface
		configuration mode.
Step 3 speed {10 100 1000 auto [10 100		This command is not available on a 10-Gigabit Ethernet interface.
	1000] nonegotiate}	Enter the appropriate speed parameter for the interface:
		• Enter 10, 100, or 1000 to set a specific speed for the interface.
		The 1000 keyword is available only for 10/100/1000 Mb/s ports.
		• Enter auto to enable the interface to autonegotiate speed with the
		connected device. If you use the 10, 100, or the 1000 keywords
		with the auto keyword, the port autonegotiates only at the
		specified speeds.
		• The nonegotiate keyword is available only for SFP module ports.
		SFP module ports operate only at 1000 Mb/s but can be
		configured to not negotiate if connected to a device that does not
		support autonegotiation.
		For more information about speed settings, see the “Speed and
		Duplex Configuration Guidelines” section on page 11-22.
Step 4
	duplex {auto full half}	This command is not available on a 10-Gigabit Ethernet interface.
		Enter the duplex parameter for the interface.
		Enable half-duplex mode (for interfaces operating only at 10 or
		100 Mb/s). You cannot configure half-duplex mode for interfaces
		operating at 1000 Mb/s.
		You can configure the duplex setting when the speed is set to auto.
		For more information about duplex settings, see the “Speed and
		Duplex Configuration Guidelines” section on page 11-22.
Step 5
	end	Return to privileged EXEC mode.
Step 6
	show interfaces interface-id	Display the interface speed and duplex mode configuration.
Step 7
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		11-23