The Modified Routing Protocol for Defending against Attacks in MANET

Mobile Ad Hoc Networks are the set of mobile hosts operating without the aid of the established infrastructure of centralized administration. Due to lack of infrastructure, the network can be easily affected by several attacks. In addition to node mobility, a MANET is characterized by limited resources such as bandwidth, battery power, and storage space. The underlying assumption in MANETs is that the intermediate nodes cooperate in forwarding packets. MANETs are mostly vulnerable to the Denial of Service (DoS) attack because of its features. For this, we have developed the reputation based system. Here, each node would evaluate nodes recommendation, route id and threshold packet dropping ratio. The proposed reputation system is evaluated with discrete event simulator environment. Simulation results shows that the reputation based system detects and isolates the DoS attack and provides better misbehavior detection efficiency, packet delivery ratio, and reduced packet dropping ratio, routing overhead, latency . Keywords-MANET, Packet Delivery Ratio, DoS attack, detection efficiency and overhead.