The Purpose of a DHCP Relay Agent

A DHCP relay agent is a network device that forwards DHCP (Dynamic Host Configuration Protocol) messages between DHCP clients and DHCP servers. Its main purpose is to extend the reach of DHCP services beyond the local subnet, allowing clients on different subnets to obtain IP address configuration information from a centralized DHCP server.

How DHCP Relay Agent Works

When a DHCP client sends a broadcast request for an IP address, the DHCP relay agent intercepts the request and forwards it to one or more DHCP servers. The relay agent includes the IP address of the DHCP server in the message header so that the server knows where to send the response.

The DHCP server receives the request, assigns an available IP address to the client, and sends the configuration information back to the relay agent. The relay agent then forwards the response to the client, completing the DHCP negotiation process.

By using a DHCP relay agent, organizations can centralize DHCP services and manage IP address assignments more efficiently across multiple subnets.