3Com Switch 7750 Series
Command Reference Guide – DHCP Chapter 2 DHCP Relay Configuration Commands
2-3
Description
Use the address-check no-matched enable command to forbid freely-connected
clients to pass DHCP security check.
Use the address-check no-matched disable command to allow freely-connected
clients to pass DHCP security check.
By default, freely-connected clients are not allowed to pass DHCP security check.
Freely-connected clients refer to the clients whose IP addresses and MAC addresses
are not in the DHCP security table.
This configuration will take effect only after the address checking function of the DHCP
relay on the VLAN interface is enabled.
Example
# Configure to not allow freely-connected clients to pass DHCP security check on
VLAN interface 1.
<3Com> system-view
System View: return to User View with Ctrl+Z.
[3Com] interface Vlan-interface 1
[3Com-Vlan-interface1] address-check enable
[3Com-Vlan-interface1] address-check no-matched enable
2.1.4 dhcp relay information enable Syntax
dhcp relay information enable
undo dhcp relay information enable
View
System view
Parameter
None
Description
Use the dhcp relay information enable command to enable option 82 supporting on
a DHCP relay, through which you can enable the DHCP relay to insert option 82 into
DHCP request packets sent to a DHCP server.
Use the undo dhcp relay information enable command to disable option 82
supporting on a DHCP relay, through which you can disable the DHCP relay from
inserting option 82 into DHCP request packets sent to a DHCP server.
By default, this function is disabled.