Packet Tracer Lab 1.3.2

How the IOS installs and removes directly connected routes is conveyed through this Packet Tracer. When a routers interface is configured with an IP address and a subnet mask, that interface becomes a host on the network. A PC is normally configured with a single host IP address because it only has a single network interface, usually an Ethernet NIC. Routers have multiple interfaces, therefore each interface must be a member of a different network. Before any static or dynamic routing is configured on a router, the router only knows about its own directly connected networks. These are the only networks that are displayed in the routing table until static or dynamic routing is configured. Directly connected networks are of prime importance for routing decisions. Static and dynamic routes cannot exist in the routing table without a router's own directly connected networks. The router cannot send packets out an interface if that interface is not enabled with an IP address and subnet mask, just as a PC cannot send IP packets out its Ethernet interface if that interface is not configured with an IP address and subnet mask.