3-8
The dhcp-snooping information format command applies only to the default content of the Option 82
field. If you have configured the circuit ID or remote ID sub-option, the format of the sub-option is ASCII,
instead of the one specified with the dhcp-snooping information format command.
Follow these steps to configure the circuit ID sub-option:
To do… Use the command… Remarks
Enter system view system-view —
Enter Ethernet port view interface interface-type
interface-number —
Configure the circuit ID
sub-option in Option 82
dhcp-snooping information
[ vlan vlan-id ] circuit-id string
string
Optional
By default, the circuit ID sub-option
contains the VLAN ID and port index
related to the port that receives DHCP
request packets from DHCP clients
z In a port aggregation group, you can use this command to configure the primary and member ports
respectively. When Option 82 is added, however, the circuit ID sub-option is subject to the one
configured on the primary port.
z The circuit ID sub-option configured on a port will not be synchronized in the case of port
aggregation.
You can configure the remote ID sub-option in system view or Ethernet port view:
z In system view, the remote ID takes effect on all interfaces. You can configure Option 82 as the
system name (sysname) of the device or any customized character string in the ASCII format.
z In Ethernet port view, the remote ID takes effect only on the current interface. You can configure
Option 82 as any customized character string in the ASCII format for different VLANs. That is to say,
you can add different configuration rules for packets from different VLANs.
Follow these steps to configure the remote ID sub-option in Option 82: