Specifications

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Cisco Catalyst Blade Switch 3020 for HP Command Reference
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Chapter 2 Cisco Catalyst Blade Switch 3020 for HP 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.
Duplex options are not supported on the 1000BASE-x (where -x is -SX) 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.
If both ends of the line support autonegotiation, we highly recommend using the default autonegotiation
settings. If one interface supports autonegotiation and the other end does not, configure duplex and speed
on both interfaces; do use the auto setting on the supported side.
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed
setting and then forces the speed setting to the negotiated value. The duplex setting remains as
configured on each end of the link, which could result in a duplex setting mismatch.
You can configure the duplex setting when the speed is set to auto.
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 Mbps). You
cannot configure half-duplex mode for interfaces operating at 1000 or
10,000 Mbps.
Release Modification
12.2(25)SEF This command was introduced.