Figure 10-16 DHCP Relay Application
To allow all clients in different VLAN request IP address from one server successfully, the
DHCP Relay function can transmit the DHCP packet between clients and server in different
VLANs, and all clients in different VLANs can share one DHCP Server.
When receiving DHCP-DISCOVER and DHCP-REQUEST packets, the switch will fill the
giaddr field with the interface IP of the receiving port, optionally insert the option 82
information, and then forward the packet to the server.
When receiving DHCP-OFFER and DHCP-REQUEST packets from the server, the switch will
delete the option 82 information and forward the packet to the interface which receives the
request.
The process will be shown as follows.
Figure 10-17 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.
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