Owners manual

DGS-1510 Series Gigabit Ethernet SmartPro Switch CLI Reference Guide
172
17. DHCP Snooping Commands
17-1 ip dhcp snooping
This command is used to globally enable DHCP snooping. Use the no command to disable DHCP
snooping.
ip dhcp snooping
no ip dhcp snooping
Parameters
None.
Default
By default, this option is disabled.
Command Mode
Global Configuration Mode.
Command Default Level
Level: 12.
Usage Guideline
The DHCP snooping function snoops the DHCP packets arriving at the untrusted interface on the VLAN
that is enabled for DHCP snooping. With this function, the DHCP packets that come from the untrusted
interface can be validated and a DHCP binding database will be constructed for the DHCP snooping
enabled VLAN. The binding database provides IP and MAC binding information that can be further used
by the IP source guard and dynamic ARP inspection process.
Example
This example shows how to enable DHCP snooping.
Switch# configure terminal
Switch(config)# ip dhcp snooping
Switch(config)#
17-2 ip dhcp snooping information option allow-untrusted
This command is used to globally allow DHCP packets with the relay Option 82 on the untrusted interface.
Use the no form of the command to not allow packets with the relay Option 82.
ip dhcp snooping information option allow-untrusted
no ip dhcp snooping information option allow-untrusted
Parameters
None.
Default
By default, this option is not allowed.