Setting The Interface Speed - Cisco Catalyst 4500 Series Configuration Manual

Configuring Optional Interface Features

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
This example shows how to allow Fast Ethernet interface 5/4 to autonegotiate the speed and duplex
mode:
Switch(config)# interface fastethernet 5/4
Switch(config-if)# speed auto
Note The proceeding cli is analogous to speed auto 10 100.
This example shows how to limit the interface speed to 10 and 100 Mbps on the Gigabit Ethernet
interface 1/1 in auto-negotiation mode:
Switch(config)# interface gigabitethernet 1/1
Switch(config-if)# speed auto 10 100
This example shows how to limit speed negotiation to 100 Mbps on the Gigabit Ethernet interface 1/1:
Switch(config)# interface gigabitethernet 1/1
Switch(config-if)# speed auto 100
Note Turning off autonegotiation on a Gigabit Ethernet interface results in the port being forced into
1000 Mbps and full-duplex mode.
To turn off the port speed autonegotiation for Gigabit Ethernet interface 1/1, perform this task:
Command
Step 1
Switch(config)# interface gigabitethernet1/1
Step 2
Switch(config-if)# speed nonegotiate
To restore autonegotiation, enter the no speed nonegotiate command in the interface configuration
mode.
For the blocking ports on the WS-X4416 module, do not set the speed to autonegotiate.
Note
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
7-20
Purpose
Specifies the interface to be configured.
Sets the interface speed of the interface.
Purpose
Specifies the interface to be configured.
Disables autonegotiation on the interface.
Chapter 7 Configuring Interfaces
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