Web Management Guide-R04

Table Of Contents
Chapter 18
| IP Services
Dynamic Host Configuration Protocol
– 707 –
Insertion of Relay Information – Enable DHCP Option 82 information relay.
(Default: Disabled)
DHCP Option Policy – Specifies how to handle client requests which already
contain DHCP Option 82 information:
Drop - Floods the original request packet onto the VLAN that received it
instead of relaying it. (This is the default.)
Keep - Retains the Option 82 information in the client request, inserts the
relay agent’s address, and unicasts the packet to the DHCP server.
Replace - Replaces the Option 82 information circuit-id and remote-id
fields in the client’s request with information provided by the relay agent
itself, inserts the relay agents address, and unicasts the packet to the DHCP
server.
DHCP Sub-option Format – Specifies whether or not to use the sub-type and
sub-length fields in the circuit-ID (CID) and remote-ID (RID) in Option 82
information. (Default: Included)
Server IP Address – Addresses of DHCP servers or relay servers to be used by
the switchs DHCP relay agent in order of preference.
Web Interface
To configure DHCP relay service:
1. Click IP Service, DHCP, Relay Option 82.
2. Enable or disable Option 82.
3. Set the Option 82 policy to specify how to handle Option 82 information
already contained in DHCP client request packets.
4. Specify whether or not include “type” and “length” sub-options.
5. Enter up to five IP addresses for DHCP servers or relay servers in order of
preference.
6. Click Apply.
Figure 476: Configuring DHCP Relay Information Option 82 Service