ADTRAN AOS Version R10.1.0 Command Reference Manual page 1613

Command Reference Guide
half-duplex
Use the half-duplex command to configure the Ethernet interface for half-duplex operation. This setting
allows the Ethernet interface to either send or receive at any given moment, but not simultaneously. Use
the no form of this command to disable half-duplex operation.
Syntax Description
No subcommands.
Default Values
By default, all Ethernet interfaces are configured for half-duplex operation.
Command History
Release 1.1
Functional Notes
Half-duplex Ethernet is the traditional form of Ethernet that employs the carrier sense multiple
access/collision detect (CSMA/CD) protocol to allow two or more hosts to share a common transmission
medium while providing mechanisms to avoid collisions. A host on a half-duplex link must "listen" on the
link and only transmit when there is an idle period. Packets transmitted on the link are broadcast (so it will
be "heard" by all hosts on the network). In the event of a collision (two hosts transmitting at once), a
message is sent to inform all hosts of the collision and a backoff algorithm is implemented. The backoff
algorithm requires the station to remain silent for a random period of time before attempting another
transmission. This sequence is repeated until a successful data transmission occurs.
Some Ethernet equipment (though rare) is unable to negotiate duplex if speed is
manually determined. To avoid incompatibilities, manually set the duplex if the speed
is manually set. Refer to
Usage Examples
The following example configures the Ethernet interface for half-duplex operation:
(config)#interface ethernet 0/1
(config-eth 0/1)#half-duplex
60000CRG0-35E
Command was introduced.
speed on page 1712
Copyright © 2012 ADTRAN, Inc.
Ethernet Interface Command Set
for more information.
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