Which routing protocol uses the concept of cost to determine the best path?

The routing protocol that utilizes the concept of cost to determine the best path is OSPF (Open Shortest Path First). In OSPF, each link (or interface) within the network is assigned a cost value, which is typically based on the bandwidth of the link; lower costs are associated with higher bandwidth. OSPF calculates the total cost of a route by summing the costs of all the links along that path, allowing it to choose the route with the lowest overall cost as the best path to reach a destination.

This cost-based metric enables OSPF to efficiently manage routing in larger networks and helps to ensure that traffic is directed through the most efficient paths, which can be particularly beneficial in complex topologies. OSPF is a link-state routing protocol, meaning it maintains a complete map of the network and updates its routing table based on the accumulated link costs, thus allowing for dynamic path selection as network conditions change.

Other protocols mentioned do not primarily use cost in the same way. For example, RIP (Routing Information Protocol) relies on hop count as its metric and does not consider link costs for path selection. EIGRP (Enhanced Interior Gateway Routing Protocol) does utilize a composite metric that includes bandwidth, delay, load,