Cisco Systems EA6500 Manual De Usuario

If you set the Ethernet port speed to auto on a 10/100-Mbps or 10/100/1000-Mbps Ethernet port, both 
speed and duplex are autonegotiated. 

To set the port speed for a 10/100 or a 10/100/1000-Mbps Ethernet port, perform this task:

This example shows how to set the speed to 100 Mbps on the Fast Ethernet port 5/4:

Router(config)# interface fastethernet 5/4

Router(config-if)# speed 100

10-Gigabit Ethernet and Gigabit Ethernet are full duplex only. You cannot change the duplex mode 
on 10-Gigabit Ethernet or Gigabit Ethernet ports or on a 10/100/1000-Mps port configured for 
Gigabit Ethernet. 

If you set the port speed to auto on a 10/100-Mbps or a 10/100/1000-Mbps Ethernet port, both speed 
and duplex are autonegotiated. You cannot change the duplex mode of autonegotiation ports. 

To set the duplex mode of an Ethernet or Fast Ethernet port, perform this task:

This example shows how to set the duplex mode to full on Fast Ethernet port 5/4:

Router(config)# interface fastethernet 5/4

Router(config-if)# duplex full

Link negotiation does not negotiate port speed.

On Gigabit Ethernet ports, link negotiation exchanges flow-control parameters, remote fault 
information, and duplex information. Link negotiation is enabled by default.

Router(config)# interface fastethernet slot/port 

Selects the Ethernet port to be configured.

Router(config-if)# speed {10 | 100 | 1000 | auto} 

Sets the speed of the Ethernet interface.

Router(config-if)# no speed 

Reverts to the default configuration (speed auto).

Router(config)# interface fastethernet slot/port 

Selects the Ethernet port to be configured.

Router(config-if)# duplex [auto | full | half] 

Sets the duplex mode of the Ethernet port.

Router(config-if)# no duplex 

Reverts to the default configuration (duplex auto).