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Catalyst 2350 Switch Command Reference
OL-19055-01
Chapter 2 Catalyst 2350 Switch Cisco IOS Commands
duplex
duplex
Use the
duplex
interface configuration command to specify the duplex mode of operation for a port. Use
the
no
form of this command to return the port to its default value.
duplex
{
auto
|
full
|
half
}
no duplex
Syntax Description
Defaults
The default is
auto
for Gigabit Ethernet ports.
You cannot configure the duplex mode on 10-Gigabit Ethernet ports; it is always
full
.
The default is
full
for the 100BASE- LX small form-factor pluggable (SFP) modules.
The default is
half
for the 100BASE-FX SFP modules.
Duplex options are not supported on the 1000BASE-
x
(where -
x
is -BX, -CWDM, -LX, -SX, or -ZX)
SFP modules.
For information about which SFP modules are supported on your switch, see the product release notes.
Command Modes
Interface configuration
Command History
Usage Guidelines
For Gigabit Ethernet ports, setting the port to
auto
has the same effect as specifying
full
if the attached
device does not autonegotiate the duplex parameter.
Note
Half-duplex mode is supported on Gigabit Ethernet interfaces if the duplex mode is
auto
and the
connected device is operating at half duplex. However, you cannot configure these interfaces to
operate in half-duplex mode.
Certain ports can be configured to be either full duplex or half duplex. Applicability of this command
depends on the device to which the switch is attached.
auto
Enable automatic duplex configuration; port automatically detects whether it
should run in full- or half-duplex mode, depending on the attached device mode.
full
Enable full-duplex mode.
half
Enable half-duplex mode (only for interfaces operating at 10 or 100 Mb/s). You
cannot configure half-duplex mode for interfaces operating at 1000 or
10,000 Mb/s.
Release
Modification
12.2(46)EY
This command was introduced.