Detection&Prevention of Gray Hole Attack in Mobile Ad-Hoc Network using AODV Routing Protocol

In MANET, the Gray Hole attack, is a node in the network start behaving like a Gray hole node that selectively drops and forwards data packets after advertises itself as having the shortest path to the destination node in response to a route request message. Mobile ad hoc networks (MANET) are widely used in places where there is little or no infrastructure. A number of people with mobile devices may connect together to form a large group. Later on they may split into smaller groups. This dynamically changing network topology of MANETs makes it vulnerable for a wide range of attack. Many researchers have given different solutions for preventing and detecting this attack. We have discussed a methodology in this survey. We are using AODV protocol for sending packet to the destination. and then introducing a gray hole node which drops the packet. To improve the performance, we are using IDS aodv technique, which enable us to minimize the attacks on integrated MANET-Internet communication efficiently. In this paper we have used AODV routing Protocol for route discovery. When malicious node starts dropping packets we use Intrusion Detection scheme to report violation of policy and the nodes whose packets are dropped again try to establish new paths using Route Requests (RREQ) messages. In our paper the NS2 scenario shows that the throughput is improved than traditional gray hole attacks.