2-1
2 DHCP Relay Agent Configuration
When configuring the DHCP relay agent, go to these sections for information you are interested in:
z Introduction to DHCP Relay Agent
z Configuring the DHCP Relay Agent
z Displaying and Maintaining DHCP Relay Agent Configuration
z DHCP Relay Agent Configuration Example
z Troubleshooting DHCP Relay Agent Configuration
Currently, the interface-related DHCP relay agent configurations can only be made on VLAN
interfaces.
Introduction to DHCP Relay Agent
Usage of DHCP Relay Agent
Since the packets are broadcasted in the process of obtaining IP addresses, DHCP is only applicable to
the situation that DHCP clients and DHCP servers are in the same network segment, that is, you need
to deploy at least one DHCP server for each network segment, which is far from economical.
DHCP relay agent is designed to address this problem. It enables DHCP clients in a subnet to
communicate with the DHCP server in another subnet so that the DHCP clients can obtain IP
addresses. In this case, the DHCP clients in multiple networks can use the same DHCP server, which
can decrease your cost and provide a centralized administration.
DHCP Relay Agent Fundamentals
Figure 2-1 illustrates a typical DHCP relay agent application.