OSPF chooses the shortest routes by calculating the cost of each path based on the bandwidth of each link in the path. The lower the total cost of a path, the shorter it is considered to be. OSPF routers use a link-state database to store information about all the routers and links in the network. They exchange link-state advertisements (LSAs) to build and maintain this database. The Shortest Path First (SPF) algorithm is then used to calculate the shortest path to each network in the network topology. OSPF chooses the path with the lowest total cost as the shortest path. In case of a tie, OSPF uses other criteria, such as the router ID and the interface cost, to make the final decision.
