DHCP option 82 support

The DHCP relay agent information option (DHCP option 82) enables a DHCP relay agent to include information about itself when forwarding client-originated DHCP packets to a DHCP server. The DHCP server uses this information to implement IP address or other parameter-assignment policies.

In a metropolitan Ethernet-access environment, the DHCP server can centrally manage IP address assignments for a large number of subscribers. If DHCP option 82 is disabled, a DHCP policy can only be applied per subnet, rather than per physical port. When DHCP option 82 is enabled, a subscriber is identified by the physical port through which it connects to the network.