3Com 4500 Switch User Manual


 
2-8
To do… Use the command… Remarks
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
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.