Analysis and Prevention of effects of gray hole attacks on Routing Protocol in Mobile Ad-hoc Networks

Abstract: Mobile Ad hoc Networks also abbreviated as MANETs, are infrastructure less wireless networks which are characterized by dynamic topologies. MANET is made up of autonomous collection of users that are continuously on the move, over bandwidth constrained wireless links. Gray hole attack is an active kind of attack on adhoc networks where the attacking node first forwards packets and then later on drops the packets resulting in Denial of Service (DoS). As MANET being a network without any central administration, is vulnerable to such kind of attacks and network can be easily crippled by such malicious nodes. Therefore various kinds of security mechanisms are applied to protect networks from harm. Intrusion Detection Systems (IDs) are one of the solution which help in detecting the misbehaving node as well as notifies other nodes in networks of the misbehaving node. The main aim of security systems is to provide services like Authentication, Accountability, Integrity, Anonymity and Confidentiality. 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.

Keywords: Ad hoc Network ,Network simulator NS-2,Security Threats, Grayhole Attacks, Routing Protocols,Performance, PDR, NRL,Packet Loss