8-6 
To do…  Use the command…  Remarks 
Configure the 
padding format for 
Option 82 
dhcp-snooping 
information format 
{ normal | verbose 
[ node-identifier { mac | 
sysname | user-defined 
node-identifier } ] } 
Optional 
normal by default. 
Configure the code 
type for the circuit ID 
sub-option 
dhcp-snooping 
information circuit-id 
format-type { ascii | hex } 
Optional 
By default, the code type 
depends on the padding 
format of Option 82. Each 
field has its own code 
type. 
This code type 
configuration applies to 
non-user-defined Option 
82 only. 
Configure 
non-user-defined 
Option 82 
Configure the code 
type for the remote 
ID sub-option 
dhcp-snooping 
information remote-id 
format-type { ascii | hex } 
Optional 
hex by default. 
The code type 
configuration applies to 
non-user-defined Option 
82 only. 
Configure the 
padding content for 
the circuit ID 
sub-option 
dhcp-snooping 
information [ vlan vlan-id ] 
circuit-id string circuit-id 
Optional 
By default, the padding 
content depends on the 
padding format of Option 
82. 
Configure 
user-defined 
Option 82 
Configure the 
padding content for 
the remote ID 
sub-option 
dhcp-snooping 
information [ vlan vlan-id ] 
remote-id string 
{ remote-id | sysname } 
Optional 
By default, the padding 
content depends on the 
padding format of Option 
82. 
 
 
z  You can enable DHCP snooping to support Option 82 on Layer 2 Ethernet interfaces only. 
z  To support Option 82, it is required to perform related configuration on both the DHCP server and 
the device enabled with DHCP snooping. 
z  If the handling strategy of the DHCP-snooping-enabled device is configured as replace, you need 
to configure a padding format for Option 82. If the handling strategy is keep or drop, you need not 
configure any padding format. 
z  If the Option 82 is padded with the device name (sysname) of a node, the device name must 
contain no spaces. Otherwise, the DHCP-snooping-enabled device will drop the message.