Configure Trusted and Untrusted Ports

Use the following procedure to set the trust factor associated with a port for DHCP Snooping. By default, the trust factor is set to untrusted.

Note

For ports that are members of an MLT, DHCP Snooping must be configured using the MLT configuration mode.

1. Enter Interface Configuration mode:

   enable

   configure terminal

   interface GigabitEthernet {slot/port[/sub-port][-slot/port[/sub-port]][,...][slot/all][all]} or interface mlt <1-512>

   

   Note

   If the platform supports channelization and the port is channelized, you must also specify the sub-port in the format slot/port/sub-port.

2. Configure the trust factor for the port:

   ip dhcp—snooping <trusted|untrusted>

   

   Note

   Configure ip dhcp-snooping trusted on a DHCP server switch port only.

Example

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#interface gigabitEthernet 1/2
Switch:1(config-if)#ip dhcp-snooping trusted