Cisco Catalyst 3750-X Command Reference

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Catalyst 3750-X and 3560-X Switch Command Reference
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Chapter 2 Catalyst 3750-X and 3560-X Switch Cisco IOS Commands
duplex
duplex
Use the duplex interface configuration command on the switch stack or on a standalone switch 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.
Duplex options are not supported on the 1000BASE-x (where -x is -BX, -CWDM, -LX, -SX, or -ZX)
SFP modules.
The default is half for 100BASE-x (where -x is -BX, -FX, -FX-FE, or - LX) small form-factor pluggable
(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 Fast Ethernet ports on stack members other than Catalyst 3750-X switches, setting the port to auto
has the same effect as specifying half if the attached device does not autonegotiate the duplex parameter.
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(53)SE2 This command was introduced.

Cisco Catalyst 3750-X Specifications

General

Brand	Cisco
Model	Catalyst 3750-X
Category	Switch
Language	English