OSPF (Open Shortest Path First) is a link-state routing protocol used in IP networks for intra-domain routing within an autonomous system. It dynamically calculates the best path using the Dijkstra Shortest Path First (SPF) algorithm, considering link cost (based on bandwidth). OSPF organizes networks into areas, with Area 0 (Backbone Area) as the core for efficient scaling. It establishes neighbor relationships via Hello packets and exchanges Link-State Advertisements (LSAs) to update topology information. Unlike distance-vector protocols, OSPF only sends updates when topology changes occur, ensuring fast convergence and reduced network overhead. It supports VLSM, CIDR, authentication, and load balancing, making it a preferred choice for large enterprise and service provider networks. Learn more: https://en.wikipedia.org/wiki/OSPF_