What is the primary purpose of a router's routing table?

What is the primary purpose of a router's routing table?

• A. To map destination networks to next-hop interfaces
• B. To store user credentials
• C. To perform DNS resolution
• D. To filter traffic

Answer: (A)

The routing table is used to decide where to forward every incoming packet. It maps destination networks to the next-hop address or exit interface, so the router knows which path to take to reach the destination. When a packet arrives, the router looks up its destination IP, applies the longest-prefix match to find the most specific route, and then forwards the packet out the corresponding interface toward that next hop. If no exact route exists, a default route may be used to send traffic toward a gateway that can reach unknown networks. Other functions aren’t handled by the routing table. Storing user credentials is part of authentication systems, DNS resolution is about translating hostnames to IP addresses, and traffic filtering is done by firewalls or access control lists.

The routing table is used to decide where to forward every incoming packet. It maps destination networks to the next-hop address or exit interface, so the router knows which path to take to reach the destination. When a packet arrives, the router looks up its destination IP, applies the longest-prefix match to find the most specific route, and then forwards the packet out the corresponding interface toward that next hop. If no exact route exists, a default route may be used to send traffic toward a gateway that can reach unknown networks.

Other functions aren’t handled by the routing table. Storing user credentials is part of authentication systems, DNS resolution is about translating hostnames to IP addresses, and traffic filtering is done by firewalls or access control lists.