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3-6
To do…
Use the command…
Remarks
Specify the current port as a
trusted port
dhcp-snooping trust
Required
By default, after DHCP
snooping is enabled, all ports of
a device are untrusted ports.
z
You need to specify the ports connected to the valid DHCP servers as trusted to ensure that DHCP
clients can obtain valid IP addresses. The trusted port and the port connected to the DHCP client
must be in the same VLAN.
z
You are not recommended to configure both the DHCP snooping and selective QinQ function on
the device, which may result in the DHCP snooping to function abnormally.
Configuring DHCP Snooping to Support Option 82
Enable DHCP snooping and specify trusted ports on the device before configuring DHCP snooping to
support Option 82.
DHCP-Snooping Option 82 Support Configuration Task List
Complete the following tasks to configure DHCP-snooping Option 82 support:
Task
Remarks
Enable DHCP-snooping Option 82 support
Required
Configure a handling policy for DHCP packets with Option 82
Optional
Configure the storage format of Option 82
Optional
Configure the circuit ID sub-option
Optional
Configure the remote ID sub-option
Optional
Configure the padding format for Option 82
Optional
Enable DHCP-snooping Option 82 support
Follow these steps to enable DHCP-snooping Option 82 support: