Mobile Ad Hoc Network (MANET) is collection of multi-hop wireless mobile nodes that can communicate with each other without centralized control or established infrastructure. The network in which wireless links are highly error prone and can go down frequently due to mobility of nodes, interference and less infrastructure. Routing in MANET is a quite difficult due to highly dynamic environment. Several routing protocols have been proposed for mobile ad hoc networks. This paper proposed OSPF routing protocol in Mobile Ad Hoc Network. Here, the router first find out the shortest path from source to destination and forwarded the packet in that path.