2.16 Direct Routing

Direct routing takes place when the source node checks the destination address and determines that it is in the same IP network, the same subnet, and the same physical network. In this case, the host uses the Address Resolution Protocol (ARP, see Section 3.4.2) to send a broadcast to the local network and map the IP address to a link layer address, e. g. an Ethernet address. The node then encapsulates the datagram into a link layer frame and directly sends it to the datagram's destination.

This ist shown in Animation 2.16-1.