Mobile Ad hoc networks typically work in an open un-trusted environment with little physical security, and are vulnerable for different type of security attacks. One attack in ad hoc networks is the wormhole attack that has received a great deal of recent attention. In wormhole attack, an attacker captures the packets from one point in the network and tunnels them to a distant location where they are replayed, typically without modification. Thus the detection of wormhole is very important in the network. For wormhole attack to have a best impact on the network, it must attract a large amount of network traffic which is done by giving a shortest route to destination in the network. Therefore, the routes going through the wormhole must be shorter than alternate routes through valid network nodes. This paper uses demonstrate different existing worm hole deduction mechanism and discuss problem in existing mechanism.

Mobile Ad hoc Network Selfish Malicious ICMP