Enhanced AODV Routing for Secure MANET Using Preventing Gray Hole Attack

Ad hock Network is a temporary network set up to share information among nodes. The network is constrained about resources and always has threat from malicious nodes. Gray hole attack is one of the attack in which, attacker node drops some packets and forward some packets and because of its behaviour its difficult to detect and prevent. In this Paper proposed a technique to identify and prevent Gray hole attacks in AODV based MANETs, in proposed approached, using AODV protocol which is widely used in MANETs and it easy to use. In Proposed work by verifying source address in the RREQ control packet named Source Node ID. This field will be used to store the value of the IP of the intermediate node that processes the RREQ. Because it checks destination sequence number and time stamp when any RREP comes from source node or and any attacker nodes. Source node will keep this field empty when it initiates the route request and forward the RREQ packet. It will keep a copy of its own RREQ. Proposed method uses the available control packets i. e. RREQ and RREP to ascertain trustworthiness of a node. Therefore, new packets like acknowledgment packets need not be introduced for proving reliability. Results are present taken with the help of the NS2 simulator, which is widely used in networking field.