Computer Science – Network hardware | e-Consult

A router uses a routing table to determine the best path for a data packet to reach its destination. The routing table is a fundamental component of a router's operation.

The routing table contains entries that map destination networks (or individual hosts) to the next hop – the next router or network to which the packet should be sent. Each entry typically includes the destination network, the next hop IP address, and a 'metric' or cost associated with that path. The metric indicates the desirability of using that path; lower metrics are generally preferred.

When a data packet arrives at the router, the router examines the packet's destination IP address. It then searches its routing table for an entry that matches the destination network. If a match is found, the routing table entry specifies the next hop – the IP address of the next router or network to which the packet should be forwarded. The router then modifies the packet's header to reflect this next hop and forwards the packet accordingly. If no exact match is found, the router will use a best-match algorithm to select the most appropriate route based on the destination IP address.