Abstract
In current years mobile ad hoc network has a superior impact on wireless communication network. In MANET, each and every node acts as a router to establish a route and transfer data by means of various hops. MANET is more vulnerable to network security problem. When a source wants to transfer data to destination, packets are transferred through the router nodes, thus, searching and establishing a route from a sender node to a receiver node is a challenging task in MANET. Routing is an important task in MANET and for this routing it has several routing protocols. AODV is one of the most suitable routing protocols for the MANET and it is more vulnerable to black hole attack by the attacker nodes, an Attacker node that incorrectly sends the route reply (RREP) that it has a latest route with minimum hop count to destination and then it drops all the receiving packets. This is black hole attack.