Which routing protocol primarily utilizes hop count as its metric?

The routing protocol that primarily utilizes hop count as its metric is RIP, which stands for Routing Information Protocol. This protocol defines a specific metric for measuring the distance to a destination network, which is simply the number of hops (or routers) that data must traverse to reach that destination. Each time a data packet passes through a router, the hop count increases by one. RIP's maximum allowable hop count is 15, which makes it suitable for smaller networks, as any network with a hop count greater than 15 is considered unreachable.

In contrast, OSPF (Open Shortest Path First) uses a more complex metric based on link cost, which is often influenced by factors like bandwidth. EIGRP (Enhanced Interior Gateway Routing Protocol) employs a composite metric that takes multiple factors into account, not just hop count, thus providing a more nuanced representation of network topology. BGP (Border Gateway Protocol), on the other hand, is designed for inter-domain routing and uses policy-based metrics such as path attributes rather than relying solely on hop count.

Therefore, RIP’s reliance on hop count as its primary metric distinctly sets it apart from these other routing protocols.