H3C Technologies H3C SecPath F1000-E - Manual (Page 59)

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DHCP Relay Agent Configuration
This chapter includes these sections:
• Introduction to DHCP Relay Agent
• DHCP Relay Agent Configuration Task List
• Displaying and Maintaining the DHCP Relay Agent
• DHCP Relay Agent Configuration Examples
• Troubleshooting DHCP Relay Agent Configuration
NOTE:
The DHCP relay agent configuration is supported only on Layer 3 Ethernet interfaces (or subinterfaces),
VLAN interfaces, and Layer 3 aggregate interfaces.
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 14 shows a typical application of the DHCP relay agent.
Figure 14 DHCP relay agent application
IP network
DHCP server
DHCP relay agent
DHCP client DHCP client
DHCP client DHCP client