3Com Switch 8800 Configuration Guide Chapter 13 DHCP Configuration
13-23
Table 13-34 Configure user address entries for DHCP server
Operation Command
Add a user address entry for DHCP
server dhcp relay security ip_address
mac_address static
Remove a user address entry for DHCP
server undo dhcp relay security ip_address

III. Enable/Disable DHCP security on a VLAN interface

If you enable the DHCP security feature on a VLAN interface, the switch performs user
address checking on the VLAN interface to prevent unauthorized binding request. If
you disable the DHCP security feature on a VLAN interface, the switch does not
perform user address checking on the VLAN interface.
Perform the following configuration in VLAN interface view.
Table 13-35 Enable/disable DHCP security on a VLAN interface
Operation Command
Enable DHCP security on a VLAN
interface dhcp relay security address-check
enable
Disable DHCP security on a VLAN
interface dhcp relay security address-check
disable
DHCP security is disabled on a VLAN interface by default.
13.4.3 Displaying and Debugging DHCP Relay
After the above configuration, you can execute the display command in any view to
display running information about DHCP Relay to verify your configuration.
Execute the debugging command in user view to debug DHCP Relay.
Table 13-36 Display and debug DHCP Relay
Operation Command
Display information about the
DHCP servers configured for
VLAN interface
display dhcp relay address { interface
vlan-interface vlan-id | all }
Display information about
legal user address entries for
DHCP server display dhcprelay-security [ ip_address ]
Enable debugging for DHCP
Relay debugging dhcp relay { all| packet | error |
event }