Routers on the Network
A router requires an IP address for every network segment to which it is connected.
In addition, the router must have a separate identity for each network it is connecting.
If, for example, a router connects four different network segments, it must have four different IP addresses and four different network interfaces.
The next slide illustrates the configuration of a router that connects four segments.
Notice that the router has an IP and MAC address for each of its ports that are connected to network segments.