What is the fundamental metric used by distance-vector routing protocols such as RIP?

• A. The total bandwidth along the path.
• B. The sum of latencies along the path.
• C. The number of hops to the destination.
• D. The reliability of the route.

Answer: (C)

Distance-vector routing protocols determine the best path by counting how many hops, or routers, a packet must traverse to reach the destination. In RIP, each route’s metric equals the number of hops to that destination, so the path with the fewest hops is chosen. This simple hop-count metric keeps the routing process lightweight, but it also imposes a limit: destinations more than 15 hops away are considered unreachable to help prevent routing loops in small networks. The other potential measures—total bandwidth, accumulated latency, or reliability—aren’t used as the basic metric in this approach; they’re associated with other routing schemes or more modern metrics, whereas RIP sticks to hop count as its core measure.