12-18
Catalyst 2928 Switch Software Configuration Guide
OL-23389-01
Chapter 12 Configuring Interface Characteristics
Configuring Ethernet Interfaces
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:
Use the
no speed
and
no duplex
interface configuration commands to return the interface to the default
speed and duplex settings (autonegotiate). To return all interface settings to the defaults, use the
default
interface
interface-id
interface configuration command.
This example shows how to set the interface speed to 10 Mb/s and the duplex mode to half on a
10/100 Mb/s port:
Switch#
configure terminal
Switch(config)#
interface fasttethernet0/3
Switch(config-if)#
speed 10
Switch(config-if)#
duplex half
This example shows how to set the interface speed to 100 Mb/s on a 10/100/1000 Mb/s port:
Switch#
configure terminal
Switch(config)#
interface gigabitethernet0/2
Switch(config-if)#
speed 100
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
|
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
Configuration Guidelines” section on page 12-17
Step 4
duplex
{
auto | full | half
}
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.
For more information about duplex settings, see the
Duplex Configuration Guidelines” section on page 12-17
.
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.
