What information does a router rely on for making packet forwarding decisions?

A router relies on its routing table to make packet forwarding decisions. The routing table is a critical database that holds information about the routes to various network destinations. When a router receives a packet, it inspects the destination IP address within that packet, and then references the routing table to determine the best next hop for that packet to reach its destination.

The routing table contains entries for different networks and specific paths that have been learned through various routing protocols or manually configured routes. Each entry typically includes the destination network, the next-hop address, and metrics that indicate the quality or preference of that route. By consulting this table, the router can efficiently forward packets to their intended destinations based on the best available paths.

Other choices do not provide the necessary information for packet forwarding. The router's configuration file contains settings and rules for the operation of the router but does not directly influence how individual packets are forwarded. The MAC address table, used at Layer 2, is relevant for frame forwarding within a local area network (LAN) but does not apply to routing at Layer 3. Lastly, the network topology map provides a visual representation of the network layout but is not utilized by routers for real-time packet forwarding decisions.