HP V1910 manual Dhcp relay agent configuration, Introduction to Dhcp relay agent, Fundamentals

DHCP relay agent configuration

Introduction to DHCP relay agent

Application environment

Since DHCP clients request IP addresses via broadcast messages, the DHCP server and clients must be on the same subnet. Therefore, a DHCP server must be available on each subnet, which is not practical.

DHCP relay agent solves the problem. Via a relay agent, DHCP clients communicate with a DHCP server on another subnet to obtain configuration parameters. Thus, DHCP clients on different subnets can contact the same DHCP server, and centralized management and cost reduction are achieved.

Fundamentals

a shows a typical application of the DHCP relay agent.

a.DHCP relay agent application

DHCP client DHCP client

		DHCP relay agent	IP	network
DHCP client	DHCP client		DHCP server

No matter whether a relay agent exists or not, the DHCP server and client interact with each other in a similar way (see the chapter “DHCP overview”). The following describes the forwarding process on the DHCP relay agent.

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