US Patent 11411911 Routing across multiple subnetworks using address mapping

A router includes routing circuitry and a plurality of ports. The routing circuitry is configured to receive from a first subnetwork, via one of the ports, a packet destined to be delivered to a target node located in a second subnetwork, to select a mapping, from among two or more mappings, depending on a topological relation between the first subnetwork and the second subnetwork, to map a Layer-3 address of the packet into a Layer-2 address using the selected mapping, and to forward the packet via another one of the ports to the Layer-2 address.