Implementation of Watchdog Protocol with AODV in Mobile Ad Hoc Network

Mobile ad hoc network (MANET) is a self-configuring network that is formed automatically via wireless links by a collection of mobile nodes without the help of a fixed infrastructure or centralized management. Due to dynamic infrastructure-less nature and lack of centralized monitoring points, the ad hoc networks are vulnerable to Black hole Attack. The network performance and reliability is broken by the attacks on ad hoc routing protocols. Many mechanisms have been proposed to overcome the Black hole Attack. A malicious node or black hole node send Route Response (RREP) incorrectly of having route to destination with minimum hop count and when sender sends the data packet to this malicious node, it drops all the packet in the network. The propose watchdog mechanism detect this black hole nodes in a MANET. This method first detects a black hole node in the network and then provide a new route to source node. In this, the performance of original-AODV and modified AODV called as watchdog-AODV (or W-AODV) in the presence of multiple black hole nodes is find out on the basis of throughput and packet delivery ratio and routing and control load.