3Com 5500-EI PWR Install Manual page 630

To do...
Enter Ethernet port view
Configure the circuit ID
sub-option in Option 82
If you have configured a circuit ID with the vlan vlan-id argument specified, and the other one
without the argument in Ethernet port view, the former circuit ID applies to the DHCP messages
from the specified VLAN; while the latter one applies to DHCP messages from other VLANs.
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.
The circuit ID sub-option configured on a port will neither be synchronized in the case of port
aggregation nor support XRN .
Configuring the remote ID sub-option
You can configure the remote ID sub-option in system view or Ethernet port view:
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.
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:
To do...
Enter system view
Configure the remote ID
sub-option in system view
Enter Ethernet port view
Configure the remote ID
sub-option in Ethernet port view
Use the command...
interface interface-type
interface-number
dhcp-snooping
information [ vlan vlan-id ]
circuit-id string string
Use the command...
system-view
dhcp-snooping
information remote-id
{ sysname | string string }
interface interface-type
interface-number
dhcp-snooping
information [ vlan vlan-id ]
remote-id string string
4-8
Remarks
—
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
Remarks
—
Optional
By default, the remote ID
sub-option is the MAC address of
the DHCP snooping device that
received the DHCP client's
request.
—
Optional
By default, the remote ID
sub-option is the MAC address of
the DHCP snooping device that
received the client's request.