Which routing protocol relies on a cost calculated based on the characteristics of a network’s interfaces?

The correct choice is based on the fact that OSPF (Open Shortest Path First) calculates the cost of routes depending on the bandwidth of the interfaces in the network. This cost metric allows OSPF to choose the most efficient route to forward packets, where a higher bandwidth results in a lower cost. The underlying formula for OSPF's cost is:

Cost = 100,000,000 / Interface Bandwidth (in bps)

This means that OSPF takes into account the speed of the links to optimize routing decisions and can adapt to changes in the network by recalculating the costs. This ability to dynamically adjust based on interface characteristics makes OSPF particularly well-suited for larger and more complex networks.

In contrast, other protocols like RIP (Routing Information Protocol) use a simple hop count to determine the best path without considering the actual performance characteristics of the links. Similarly, while EIGRP (Enhanced Interior Gateway Routing Protocol) uses a composite metric that includes bandwidth, delay, load, and reliability, it does not solely rely on costs derived from interface characteristics in the same straightforward manner that OSPF does. IS-IS (Intermediate System to Intermediate System) also utilizes a cost metric but is structured differently and is