Defending against packet dropping attack using DRI & cross checking mechanism in MANET

Mobile Ad hoc Network (MANET) is a type of Ad hoc Network which changes its location and configures itself. MANETs have been broadly applied in various fields, such as military, health monitoring, and environment observation. It is a self-configuring infrastructure less network. A major advantage of MANET is its wireless nature as can be deployed more rapidly and less expensively than wired networks. Despite its mobility, decentralized control and dynamic topology MANET is vulnerable to wide range of attacks. It is very difficult to detect some attacks when it becomes part of network. Ad hoc on demand distance vector (AODV) is a popular routing protocol but exposed to well known packet dropping attack, where a malicious node intentionally drops packets without forwarding them to destination. When groups of node act collaboratively to drop packets in network, the message communication in network may be severely degraded and sometime completely disrupted. In this paper, we discuss a security mechanism to defend against packet dropping attack in MANET & results are simulated with ns-2.