Operation Manual

Table Of Contents
149
Figure 9-5 DHCP Relay Application
To allow all clients in different VLANs request IP address from one server successfully, the
DHCP Relay function can transmit the DHCP packets between clients and server in different
VLANs.
When receiving DHCP-DISCOVER and DHCP-REQUEST packets, the switch will fill the
giaddr field with its own management IP address, optionally insert the option 82
information, and then forward the packet to the server.
When receiving DHCP-OFFER and DHCP-ACK packets from the server, the switch will
delete the option 82 information and forward the packets to the port which receives the
request.
The process is shown as follows.
Figure 9-6 DHCP Relay Process
DHCP Relay Configuration
1) Configure the Option 82 parameters to record the information of the clients. You are
suggested to configure the option82 on the nearest Relay of the client.
2) Specify the DHCP Server which assigns IP addresses actually.