How does OSPF handle bandwidth during cost calculation?

OSPF (Open Shortest Path First) calculates the cost of a route based on a reference bandwidth that is used to derive the cost of each link. The reference bandwidth is typically set to 100 Mbps by default, and the cost of a link is calculated as the reference bandwidth divided by the bandwidth of the link in question. This means that for each link, a lower actual bandwidth results in a higher cost.

Using a reference bandwidth allows network administrators to easily manage and adjust the cost values to reflect the relative speed of different links in the network. This method ensures that OSPF prefers faster links (which have lower costs) over slower ones when determining the best path for routing data. By calculating costs in this way, OSPF can effectively make routing decisions that optimize network performance based on the actual capabilities of the links in use.