# duplex

#### Syntax

duplex duplexMode

no duplex

#### Release Information

Command introduced before JunosE Release 7.1.0.

#### Description

Specifies the duplex mode for an Ethernet interface. This command works with the speed command; if you set or accept the automatically negotiate setting for either duplex mode or speed, the router negotiates both parameters with the remote device. The no version specifies the default value, automatically negotiate or full duplex (FE-8 SFP I/O module only). This command is not available for the Ethernet interface on the SRP module.

#### Options

- duplexMode—One of the following duplex options
  - automatically negotiate—Specifies that the router negotiates duplex mode with the remote device; not valid for the FE-8 SFP I/O module
  - full—Specifies that the router uses full duplex on a Fast Ethernet or Gigabit Ethernet interface
  - half—Specifies that the router uses half duplex on a Fast Ethernet interface; this value is not valid for Gigabit Ethernet interfaces

#### Mode

Interface Configuration