Dhcp Relay Agent Configuration; Introduction To Dhcp Relay Agent; Application Environment; Fundamentals - 3Com S7906E Configuration Manual

3

DHCP Relay Agent Configuration

When configuring the DHCP relay agent, go to these sections for information you are interested in:

Introduction to DHCP Relay Agent

DHCP Relay Agent Configuration Task List
Configuring the DHCP Relay Agent
Displaying and Maintaining DHCP Relay Agent Configuration
DHCP Relay Agent Configuration Examples
Troubleshooting 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 for ease of centralized management and cost reduction.

Fundamentals

Figure 3-1 shows a typical application of the DHCP relay agent.
Figure 3-1 DHCP relay agent application
DHCP client DHCP client
DHCP client
No matter whether a relay agent exists or not, the DHCP server and client interact with each other in a
similar way (see section
forwarding process on the DHCP relay agent.
DHCP relay agent
DHCP client
Dynamic IP Address Allocation
IP network
DHCP server
Process). The following describes the
3-1