DHCP snooping Option 82 support configuration example

As shown in Figure 38, enable DHCP snooping and Option 82 support on Switch B.

• Configure the handling strategy for DHCP requests containing Option 82 as replace.

• On 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 GigabitEthernet 1/0/3, configure the padding format as verbose, access node identifier as sysname, and code type as ascii for Option 82.

• Switch B forwards DHCP requests to the DHCP server (Switch A) after replacing Option 82 in the requests, so that the DHCP clients can obtain IP addresses.

# Enable DHCP snooping.

<SwitchB> system-view
[SwitchB] dhcp-snooping

# Specify GigabitEthernet 1/0/1 as trusted.

[SwitchB] interface GigabitEthernet 1/0/1
[SwitchB-GigabitEthernet1/0/1] dhcp-snooping trust
[SwitchB-GigabitEthernet1/0/1] quit

# Configure GigabitEthernet 1/0/2 to support Option 82.

[SwitchB] interface GigabitEthernet 1/0/2
[SwitchB-GigabitEthernet1/0/2] dhcp-snooping information enable
[SwitchB-GigabitEthernet1/0/2] dhcp-snooping information strategy replace
[SwitchB-GigabitEthernet1/0/2] dhcp-snooping information circuit-id string company001
[SwitchB-GigabitEthernet1/0/2] dhcp-snooping information remote-id string device001
[SwitchB-GigabitEthernet1/0/2] quit

# Configure GigabitEthernet 1/0/3 to support Option 82.

[SwitchB] interface GigabitEthernet 1/0/3
[SwitchB-GigabitEthernet1/0/3] dhcp-snooping information enable
[SwitchB-GigabitEthernet1/0/3] dhcp-snooping information strategy replace
[SwitchB-GigabitEthernet1/0/3] dhcp-snooping information format verbose node-identifier sysname
[SwitchB-GigabitEthernet1/0/3] dhcp-snooping information circuit-id format-type ascii
[SwitchB-GigabitEthernet1/0/3] dhcp-snooping information remote-id format-type ascii