Cisco Router Configuration, Second Edition

IP Routing Configuration

Assigning a unique IP address to every device in the network is necessary but not sufficient to enable them to communicate with one another. Devices in an IP network must also know the path or the route to other devices within the same autonomous network or within the Internet to send data packets between one another. Rather than every device in a network having a complete list of all other devices and where they reside on that network, the router acts as a sort of traffic director, performing two functions for the IP network.

First, the router receives packets from a station, determines the optimal path to the destination, and then places the packet on the next LAN or WAN segment that leads to that destination. This ...