Black Hole and Greyhole Attack in Wireless Mesh Network

Security is an important need in wireless mesh networks to give safe and shared information between wireless non-static nodes. In wireless network nodes has ability to act correctly and route the packets. Wireless mesh networks unusual method of producing,keeping and sharing information ability of mobile objects to show spontaneous and cheap adjusting arrangement itself.There are different types of communication devices in technology by which performance is measured.There is a major issue which take part in network and provide security from various kinds of malicious attacks.There are various attacks such as black hole attack,wormhole attack,Greyhole attack, and evesdropping attack.Black hole and Greyhole attacks are network layer attacks that spoils the performance by falling the packets.The black hole and Grey hole are the problem of security that consider in wireless networks.Black hole and Greyhole attack is one type of way of interrupting attack and can cause large amount of damage to network.Black hole attack is act like ad-hoc network; which create network and attack on packets.In black hole attack where a false node not make correct paths in public to receiver node during the direction finding process. Theattacker achieves this attack when all the similar kinds of nodes communicate and make network to each other. It is very important to protectthe network layer from these attack which is also a great issues in wireless mesh network. Greyhole attack is very difficult to detect in wireless mesh network.In this paper,its an overview about black hole attack and grey hole in wireless mesh network and define problem statement about them. Secondly, its take study about related work in which many authors perform on these attacks and then its discuss about proposed method.Thirdly,the results are simulated carried out in OPNET simulator where black hole attack and grey hole attack shows the performance and Its analysis the throughput in network. Keywords---Black hole attack, Grey hole attack,MRP, OLSR, RREQ, RREP,RERR,OPNET.