# dhcp-external duplicate-mac-address

#### Syntax

[ no ] dhcp-external duplicate-mac-address

#### Release Information

Command introduced in JunosE Release 9.3.0.

#### Description

Configures the DHCP external server application to use a combination of the MAC address and the gateway IP address (giaddr) to uniquely identify DHCP clients attached to the router. This behavior is also referred to as duplicate MAC mode. The no version restores the default behavior, also known as unique MAC mode, which uses only the MAC address to uniquely identify DHCP clients.

#### Mode

Global Configuration

#### Related Documentation

- DHCP External Server Identification of Clients with Duplicate MAC Addresses Overview
- Configuring DHCP External Server to Uniquely Identify Clients with Duplicate MAC Addresses