Subscriber Services: Interface-level subscriber redundancy with DHCP topology discovery

You can configure DHCP active leasequery with topology discovery to provide interface-level subscriber redundancy between peer relay agents. Topology discovery enables primary and backup peer relay agents to determine the access interfaces on peers that correspond to their own local access interfaces for servicing subscriber redundancy groups. During synchronization, DHCP translates the subscriber binding information to use the local interface on the backup instead of the interface on the primary. You must use topology discovery when you configure M:N subscriber redundancy.