4-8
[SwitchB-GigabitEthernet1/0/1] dhcp-snooping trust
[SwitchB-GigabitEthernet1/0/1] quit
DHCP Snooping Option 82 Support Configuration Example
Network requirements
z
As shown in
Figure 4-3
, enable DHCP snooping and Option 82 support on Switch B.
z
Configure the handling strategy for DHCP requests containing Option 82 as
replace
.
z
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
.
z
On GigabitEthernet 1/0/3, configure the padding format as
verbose
, access node identifier as
sysname
, and code type as
ascii
for Option 82.
z
Switch B forwards DHCP requests to the DHCP server after replacing Option 82 in the requests, so
that the DHCP clients can obtain IP addresses.
Configuration procedure
# 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