Which metric does OSPF use to determine the best path?

Which metric does OSPF use to determine the best path?

• A. Hop Count
• B. Delay
• C. Bandwidth-Based Cost
• D. Reliability

Answer: (C)

OSPF determines the best route using a cost metric that is based on link bandwidth, and it uses Dijkstra’s shortest path algorithm to pick the path with the lowest total cost. Each link has a cost, and higher-bandwidth links have lower costs. The total path cost is the sum of these per-link costs, so a route with fast links can be preferred even if it has more hops. By default, cost is calculated from a reference bandwidth divided by the link’s bandwidth (for example, with a 100 Mbps reference, a 100 Mbps link costs 1, a 10 Mbps link costs 10). Delay and reliability aren’t the primary metrics OSPF uses, and hop count is the metric used by RIP, not OSPF.

OSPF determines the best route using a cost metric that is based on link bandwidth, and it uses Dijkstra’s shortest path algorithm to pick the path with the lowest total cost. Each link has a cost, and higher-bandwidth links have lower costs. The total path cost is the sum of these per-link costs, so a route with fast links can be preferred even if it has more hops. By default, cost is calculated from a reference bandwidth divided by the link’s bandwidth (for example, with a 100 Mbps reference, a 100 Mbps link costs 1, a 10 Mbps link costs 10). Delay and reliability aren’t the primary metrics OSPF uses, and hop count is the metric used by RIP, not OSPF.