Configuring Option 82 Support On Dhcp Relay Agent - H3C S9500 Series Operation Manual

Operation Manual – DHCP
H3C S9500 Series Routing Switches
packet contains the MAC address and VLAN ID of the receiving port of the switch,
and the MAC address of the DHCP relay agent.
5) After receiving the DHCP request packet forwarded by the DHCP relay agent, the
DHCP server records the information carried by the option. Then, the DHCP
server sends to the DHCP relay agent a response packet which carries the DHCP
configuration information and Option 82 information.
6) After receiving the response packet sent by the DHCP server, the DHCP relay
agent strips Option 82 information in the packet. Then, it forwards the packet that
carries the DHCP configuration information to the DHCP client.
Note:
The request packets sent by a DHCP client fall into four types: DHCP_DISCOVER,
DHCP_REQUEST, DHCP_RELEASE and DHCP_INFORM. The DHCP relay agent
adds Option 82 into the four types of request packets. This is because the DHCP
servers from different manufacturers process the request packets in different ways.
Some of them process Option 82 in the DHCP_DISCOVER packets, while others
process Option 82 in the DHCP_REQUEST packets.

3.2.2 Configuring Option 82 Support on DHCP Relay Agent

I. Configuration prerequisites
Before enabling Option 82 support on DHCP relay agent, you should configure:
The network parameters and the relay functions on the DHCP relay agent.
The network parameters, and the address pools and the address lease on the
DHCP server.
A route between the DHCP relay agent and the DHCP server.
Chapter 3 DHCP Relay Agent Configuration
3-13