Configuring Ethernet Interface Speed And Duplex Mode - Cisco 4500M Software Manual

Chapter 4 Configuring Interfaces

Configuring Ethernet Interface Speed and Duplex Mode

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Speed and Duplex Mode Configuration Guidelines
You do not configure the client device for autonegotiation. Rather, you configure the switch with the
Note
speed, or range of speeds, that you want to autonegotiate.
You can configure the interface speed and duplex mode parameters to auto and allow the Catalyst 4500
series switch to negotiate the interface speed and duplex mode between interfaces. If you decide to
configure the interface speed and duplex commands manually, consider the following:
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Changing the interface speed and duplex mode configuration might shut down and restart the interface
Caution
during the reconfiguration.
Setting the Interface Speed
If you set the interface speed to auto on a 10/100-Mbps Ethernet interface, speed and duplex are
autonegotiated. The forced 10/100 autonegotiation feature allows you to limit interface speed auto
negotiation up to 100 Mbps on a 10/100/1000BASE-T port.
To set the port speed for a 10/100-Mbps Ethernet interface, perform this task:
Command
Step 1
Switch(config)# interface fastethernet slot/interface
Step 2
Switch(config-if)# speed [10 | 100 | auto [10 | 100] ]
This example shows how to set the interface speed to 100 Mbps on the Fast Ethernet interface 5/4:
Switch(config)# interface fastethernet 5/4
Switch(config-if)# speed 100
OL-6696-01
Speed and Duplex Mode Configuration Guidelines, page 4-7
Setting the Interface Speed, page 4-7
Setting the Interface Duplex Mode, page 4-8
Displaying the Interface Speed and Duplex Mode Configuration, page 4-9
Adding a Description for an Interface, page 4-9
If you enter the no speed command, the switch automatically configures both interface speed and
duplex to auto.
When you set the interface speed to 1000 (Mbps) or auto 1000, the duplex mode is full duplex. You
cannot change the duplex mode.
If the interface speed is set to 10 or 100, the duplex mode is set to half duplex by default unless you
explicitly configure it.
Configuring Optional Interface Features
Purpose
Specifies the interface to be configured.
Sets the interface speed of the interface.
Software Configuration Guide—Release 12.2(25)EW
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