CCNA R&S Question of the Week: Calculate OSPF Cost

Answer: A.

Nowhere in the RFC for OSPF does it define how to calculate cost, just that there is a cost on every interface. If you add up all the costs and cheapest cost wins for best path. Many moons ago it was decided to automate the process and use an auto cost bandwidth reference (a constant) divided by the bandwidth.  The default on Cisco IOS routers is 100,000,000 (100 meg) divided by the bandwidth.  The lowest possible value is 1, therefore any link speed of 100Megabits per second or fast will have the cost of 1.