Which metric does the Routing Information Protocol (RIP) use to make path decisions?

Routing Information Protocol (RIP) uses hop count as its primary metric to determine the best path for routing packets. In RIP, each route is defined by the number of hops, which refers to the number of routers a packet must pass through to reach its destination. The metric is straightforward and easy to calculate, making RIP a simple routing protocol.

When a router evaluates multiple routes to the same destination, it selects the one with the lowest hop count. A route with fewer hops is generally considered to be more efficient, as it typically implies a shorter path and less latency. However, RIP has a maximum limit of 15 hops; a route with 16 hops is treated as unreachable, which helps in preventing routing loops in the network.

This metric is particularly advantageous for smaller networks where paths are relatively short, but it does not take into account factors such as bandwidth, delay, or load, which could result in suboptimal routing decisions in larger or more complex networks. Other protocols may incorporate these factors for more refined routing decisions, but RIP's hop count metric remains a fundamental characteristic of its operation.