Specifications

Command Reference Guide Ethernet Interface Configuration Command Set

full-duplex

Use the full-duplex command to configure the Ethernet interface for full-duplex operation. This allows the

interface to send and receive simultaneously. Use the no form of this to return to the default half-duplex

operation.

Syntax Description

No subcommands

Default Values

By default, all Ethernet interfaces are configured for half-duplex operation.

Command Modes

(config-eth 0/1)# Ethernet Interface Configuration Mode required

Command History

Release 1.1 Command was introduced

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, it is not safe to assume that one vendor’s equipment will work with another.

Devices at each end of a full-duplex link have the ability to send and receive data simultaneously 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.

The 10BaseT, 100BaseTX, and 100BaseFX signalling systems support full-duplex operation (because they

have transmit and receive signal paths that can be simultaneously active).

If the speed is manually set to 10 or 100, the duplex must be manually configured as

full-duplex or half-duplex. See speed <rate> on page 325 for more information.

Usage Examples

The following example configures the Ethernet interface for

full-duplex

operation:

(config)#

interface ethernet 0/1

(config-eth 0/1)#

full-duplex