2-8
To do… Use the command… Remarks
Enter system view system-view —
Enable Option 82 support on the
DHCP relay agent dhcp relay information
enable Required
Disabled by default.
Configure the strategy for the DHCP
relay agent to process request
packets containing Option 82
dhcp relay information
strategy { drop | keep |
replace }
Optional
By default, the replace
strategy is adopted
z By default, with the Option 82 support function enabled on the DHCP relay agent, the DHCP relay
agent will adopt the replace strategy to process the request packets containing Option 82.
However, if other strategies are configured before, then enabling the 82 support on the DHCP relay
agent will not change the configured strategies.
z To enable Option 82, you need to perform the corresponding configuration on the DHCP server
and the DHCP relay agent.
Displaying and Maintaining DHCP Relay Agent Configuration
To do… Use the command… Remarks
Display the information about a specified
DHCP server group display dhcp-server groupNo
Display the information about the DHCP
server group to which a specified VLAN
interface is mapped
display dhcp-server interface
vlan-interface vlan-id
Display the specified client address
entries on the DHCP relay agent display dhcp-security [ ip-address
| dynamic | static | tracker ]
Available in any
view
Clear the statistics information of the
specified DHCP server group reset dhcp-server groupNo Available in user
view
DHCP Relay Agent Configuration Example
Network requirements
As shown in Figure 2-4, VLAN-interface 1 on the DHCP relay agent (Switch A) connects to the network
where DHCP clients reside. The IP address of VLAN-interface 1 is 10.10.1.1/24 and IP address of
VLAN-interface 2 is 10.1.1.2/24 that communicates with the DHCP server 10.1.1.1/24. As shown in the
figure below, Switch A forwards messages between DHCP clients and the DHCP server to assign IP
addresses in subnet 10.10.1.0/24 to the clients.