3Com Switch 8807, Command Reference Manual

Page: 860 / 1099

858 C
HAPTER
47: DHCP C
ONFIGURATION
C
OMMANDS
Example
# Set the system name as the node identifier when the mode of the relay option
82 on VLAN interface 1 is 3Com fixed network mode.
<SW8800> system-view
System View: return to User View with Ctrl+Z
[SW8800]interface vlan1
[3Com-Vlan-interface1] dhcp relay information format verbose
node-identifier sysname
# Restore the default node identifier of the user when the mode of relay option 82
on VLAN interface 1 is 3Com fixed network mode.
[3Com-Vlan-interface1] undo dhcp relay information format verbose
node-identifier
dhcp server relay
information enable
Syntax
dhcp server relay information enable
undo dhcp server relay information enable
View
System view
Parameter
None
Description
Use the dhcp server relay information enable command to enable the function
of Option 82 support on DHCP server.
Use the undo dhcp server relay information enable command to disable the
function of Option 82 support on DHCP server.
When a client connected to a DHCP relay broadcasts a DHCP request packet, the
DHCP relay is responsible for forwarding the packet to a DHCP server. After Option
82 support is enabled on the DHCP server, if the request packet forwarded by the
DHCP relay to the DHCP server carries Option 82, the response packet sent by the
DHCP server will carry a response Option 82.
After receiving the response packet from the DHCP server to the DHCP client, the
DHCP relay check whether Option 82 exists in the packet. If yes, it strips Option
82. That is, the response packet sent to the client does not carry Option 82.
By default, the function is enabled. That is, the DHCP server will return Option 82
carried in the request packet to the DHCP relay.
Related command: dhcp relay information enable .
Example
# Enable the DHCP server to return Option 82 carried in the request packets to the
DHCP relay.