Example: Configuring DHCP snooping support for Option 82
Network configuration
As shown in Figure 35, enable DHCP snooping and configure Option 82 on Switch B as follows:
Configure the handling strategy for DHCP requests that contain Option 82 as replace.
On Ten-GigabitEthernet 1/0/2, configure the padding content for the Circuit ID sub-option as company001 and for the Remote ID sub-option as device001.
On Ten-GigabitEthernet 1/0/3, configure the padding mode for the Circuit ID sub-option as verbose, access node identifier as sysname, and padding format as ascii. Configure the padding content for the Remote ID sub-option as device001.
Figure 35: Network diagram
Procedure
![[IMPORTANT: ]](images/important.png) | IMPORTANT: By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface. | |
# Enable DHCP snooping.
<SwitchB> system-view [SwitchB] dhcp snooping enable
# Configure Ten-GigabitEthernet 1/0/1 as a trusted port.
[SwitchB] interface ten-gigabitethernet 1/0/1 [SwitchB-Ten-GigabitEthernet1/0/1] dhcp snooping trust [SwitchB-Ten-GigabitEthernet1/0/1] quit
# Configure Option 82 on Ten-GigabitEthernet 1/0/2.
[SwitchB] interface ten-gigabitethernet 1/0/2 [SwitchB-Ten-GigabitEthernet1/0/2] dhcp snooping information enable [SwitchB-Ten-GigabitEthernet1/0/2] dhcp snooping information strategy replace [SwitchB-Ten-GigabitEthernet1/0/2] dhcp snooping information circuit-id string company001 [SwitchB-Ten-GigabitEthernet1/0/2] dhcp snooping information remote-id string device001 [SwitchB-Ten-GigabitEthernet1/0/2] quit
# Configure Option 82 on Ten-GigabitEthernet 1/0/3.
[SwitchB] interface ten-gigabitethernet 1/0/3 [SwitchB-Ten-GigabitEthernet1/0/3] dhcp snooping information enable [SwitchB-Ten-GigabitEthernet1/0/3] dhcp snooping information strategy replace [SwitchB-Ten-GigabitEthernet1/0/3] dhcp snooping information circuit-id verbose node-identifier sysname format ascii [SwitchB-Ten-GigabitEthernet1/0/3] dhcp snooping information remote-id string device001
Verifying the configuration
# Display Option 82 configuration information on Ten-GigabitEthernet 1/0/2 and Ten-GigabitEthernet 1/0/3 on the DHCP snooping device.
[SwitchB] display dhcp snooping information