Configuring Internet Protocol (IP) routing

Configuring Internet Protocol (IP) routing

IP routing is a set of mechanisms through which a computer determines where to forward an IP packet so that it can arrive at the ultimate destination IP address. If the sending machine and the ultimate destination machine are physically connected via a serial line or local area network, the sending machine can send the packet to the destination directly. If the two machines are not physically connected, the sending machine must identify intermediary machines that can forward the packet until it reaches the ultimate destination. These forwarding machines are referred to as routers.

This chapter covers the configuration and administration of IP routing on both routers (machines that not only transmit their own packets, but forward packets received but not addressed to them) and nonrouters (machines that transmit their own IP packets, but ignore any packets they receive that are not addressed to themselves). In addition, this chapter includes descriptions of how IP routing works with SCO TCP/IP.

Generally speaking, configuration of a router is determining how that machine will learn about the existence of networks not directly connected to itself so the machine may forward packets addressed to machines on those networks. Configuration of a nonrouter is determining how that machine will know about the existence of routers on the same network as itself so that the nonrouter can transmit packets to machines not on the same network as itself.