ZyXEL Communications GS-2724 - Manual (Page 181)

Chapter 27 DHCP
GS-2724 User’s Guide
181
27.4 DHCP Relay
Configure DHCP relay on the Switch if the DHCP clients and the DHCP server are not in the
same subnet. During the initial IP address leasing, the Switch helps to relay network
information (such as the IP address and subnet mask) between a DHCP client and a DHCP
server. Once the DHCP client obtains an IP address and can connect to the network, network
information renewal is done between the DHCP client and the DHCP server without the help
of the Switch.
27.4.1 DHCP Relay Agent Information
The Switch can add information to client DHCP requests that it relays to a DHCP server. This
helps provide authentication about the source of the requests. You can also specify additional
information for the Switch to add to the client DHCP requests that it relays to the DHCP
server. Please refer to RFC 3046 for more details.
The DHCP relay agent information feature adds an Agent Information field to the option 82
field of the DHCP headers of client DHCP request frames that the Switch relays to a DHCP
server. The following lists the DHCP relay agent option 82 information that the Switch sends
to the DHCP server:
• Slot ID (1 byte)
• Port ID (1 byte)
• VLAN ID (2 bytes)
• System name (up to 32 bytes, this is optional)
27.4.2 Configuring DHCP Relay
Configure DHCP relay in the DHCP Relay screen. Click IP Application > DHCP > Relay to
display the screen as shown.
Figure 87 DHCP Relay