What is the primary role of a route table in IP networking?

• A. Maintains a list of MAC addresses for switching.
• B. Stores VLAN to port mappings.
• C. Defines rules for forwarding IP packets using longest prefix match.
• D. Monitors link status and redundancy.

Answer: (C)

The route table guides how IP packets are forwarded across networks. It contains entries that map destination network prefixes to the next-hop IP address or to a specific outgoing interface. When a router or host needs to forward a packet, it searches the route table and uses the longest prefix match—the most specific network that fits the destination IP—to pick the correct route. This decision determines which interface to send the packet out of and where to forward it next, possibly using a default route if no more specific match exists. Routes can be static or learned through routing protocols, and they may include metrics or administrative distance to resolve multiple possible paths.

Other options describe different layers or functions: a MAC address table is used by switches to forward frames at layer 2; VLAN-to-port mappings are about how switches segregate and forward traffic within a single network segment; monitoring link status and redundancy relates to network availability rather than IP forwarding decisions.