Ethernet Interface Configuration Command Set
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duplex [full | half]
Purpose
Use the duplex [full | half] command to configure the Ethernet interface for either half- or full-
duplex operation. Use the no
form of this to return to the default half-duplex operation.
NOTE
This command should only be used if autonegotiation is disabled
(using the no autonegotiation command). Using autonegotiation
allows the Ethernet interface to automatically configure the speed
and duplex. If the speed is manually set to 10 or 100, the duplex
must be manually configured as duplex full or duplex half.
Syntax Description
displays the syntax descriptions for the duplex [full | half] command.
Default Values
By default, all Ethernet interfaces are configured for half-duplex operation.
Command Modes
The Ethernet Interface Configuration Mode is required for this command.
Functional Notes
Full-duplex Ethernet is a variety of Ethernet technology currently being standardized by the
IEEE. Because there is no official standard, vendors are free to implement their independent
versions of full-duplex operation. Therefore, vendor compatibility cannot be assumed.
Devices at each end of a full-duplex link have the ability to send and receive data simulta-
neously over the link. Theoretically, this simultaneous action can provide twice the bandwidth
of normal (half-duplex) Ethernet. To deploy full-duplex Ethernet, each end of the link must
only connect to a single device (a workstation or a switched hub port). With only two devices
on a full-duplex link, there is no need to use the medium access control mechanism (to share
the signal channel with multiple stations) and listen for other transmissions or collisions
before sending data.
Table 17. Syntax Description for duplex [full | half]
Syntax
Description
full
Allows the Ethernet interface to send and receive information simultaneously.
half
Allows the Ethernet interface to either send or receive at any given moment, but
not simultaneously.
