3Com Switch 7750 Configuration Guide Guide

584 CHAPTER 55: DHCP RELAY CONFIGURATION
■ Configure network parameters and relay function of the DHCP relay device.
■ Perform assignment strategy-related configurations, such as network
parameters of the DHCP server, address pool, and lease time.
■ The routes between the DHCP relay and the DHCP server are reachable.
Enabling option 82 supporting on a DHCP relay
The following operations need to be performed on a DHCP relay-enabled network
device.
n
To enable option 82, you need to perform the corresponding configuration on the
DHCP server and the DHCP relay.
Displaying and
Debugging DHCP
Relay
After the preceding configurations, you can execute the display command in any
view to verify the configurations. You can also execute the reset command to
clear the statistics information about the specified DHCP server group.
DHCP Relay
Configuration
Example
Network requirements
The DHCP clients on the network segment 10.110.0.0/16 are connected to a port
of VLAN 2. The IP address of the DHCP server is 202.38.1.2. DHCP packets
between the DHCP clients and the DHCP server are forwarded by the DHCP relay,
through which the DHCP clients can obtain IP addresses and related configuration
information from the DHCP server.
Tabl e 458 Enable option 82 supporting on a DHCP relay
Operation Command Description
Enter system view system-view -
Enable option 82 supporting
on the DHCP relay
dhcp relay information
enable
Required
By default, this function is
disabled
Configure the strategy for the
DHCP relay to process request
packets containing option 82
dhcp relay information
strategy { drop | keep |
replace }
Optional
By default, the replace policy
is adopted
Tabl e 459 Display DHCP relay information
Operation Command Description
Display the information about
a specified DHCP server group
display dhcp-server
groupNo
The display command can be
executed in any view
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 address
information of all the users in
the valid user address table of
the DHCP server group
display dhcp-security [
ip-address | dynamic | static ]
Clear the statistics
information of the specified
DHCP server group
reset dhcp-server groupNo
The reset command can be
executed in user view