Configuring the DHCP Relay Agent

Configuring the DHCP Relay Agent

The dhcp_relay program is a subnet agent that communicates with the main DHCP server to provide DHCP and proclaim clients with host configuration information. If your site uses DNS to maintain the hosts map, you need some external mechanism (such as a script) to update the DNS map from the DHCP server. If your site uses NIS to maintain the hosts and ethers maps, your site's main DHCP server must be on the same machine as the NIS master. In any case, you should run dhcp_relay on all subnets besides the one with the main DHCP server.

The DHCP relay agent reads the configuration file /var/dhcp/config/dhcp_relay.servers to determine the location of the main DHCP server. This configuration file should contain the IP address and hostname of the DHCP server, on two separate lines.

To configure the relay agent, you can run the ProclaimRelayMgr graphical interface, as described by the ProclaimRelayMgr(1M) reference page. If you prefer, you can configure relay agent options using your favorite text editor, following the steps documented on the dhcp_relay(1M) reference page.