Access Control Lists

3-105

3
CLI – This example enables DHCP Snooping Information Option, and sets the policy
as replace.

DHCP Snooping Port Configuration

Use the DHCP Snooping Port Configuration page to configure switch ports as
trusted or untrusted.
Command Usage
A trusted interface is an interface that is configured to receive only messages from
within the network. An untrusted interface is an interface that is configured to
receive messages from outside the network or fire wall.
When DHCP snooping is enabled both globally and on a VLAN, DHCP packet
filtering will be performed on any untrusted ports within the VLAN.
When an untrusted port is changed to a trusted port, all the dynamic DHCP
snooping bindings associated with this port are removed.
Set all ports connected to DHCP servers within the local network or fire wall to
trusted state. Set all other ports outside the local network or fire wall to untrusted
state.
Command Attributes
Trust Status – Enables or disables port as trusted. (Default: Untrusted)
Console(config)#ip dhcp snooping information option 4-136
Console(config)#ip dhcp snooping information policy replace 4-137
Console#show ip dhcp snooping 4-138
Global DHCP Snooping status: disable
DHCP Snooping Information Option Status: disable
DHCP Snooping Information Policy: replace
DHCP Snooping is configured on the following VLANs:
Verify Source Mac-Address: enable
Interface Trusted
---------- ----------
Eth 1/1 No
Eth 1/2 No
Eth 1/3 No
.
.
.