Option 82, or the Relay Information Option is a field in DHCP messages used to identify the subscriber. The Option 82 field can already be filled in when a DHCP message is received at the router, or it can be empty. If the field is empty, the router should add identifying information (circuit ID, remote ID or both). If the field is not empty, the router can decide to replace it.
The following output displays an example of a partial BSA configuration with Option 82 adding on a VPLS service. Snooping must be enabled explicitly on a SAP.
A:ALA-1>config>service>vpls#
----------------------------------------------
no shutdown
description "Default tls description for service id 1"
sap 1/1/11 split-horizon-group "2dslam" create
dhcp
no description
snoop
no lease-populate
option
action replace
circuit-id ascii-tuple
no remote-id
exit
no shutdown
exit
exit
----------------------------------------------
A:ALA-1>config>service>vpls#