Addressing node isolation attack in OLSR protocol

Mobile ad hoc networks (MANETs) is a self-configure, a highly dynamic network changing topology and infrastructure less. The MANETs don´t have any fixed infrastructure or central access points and they aren´t using any backbone infrastructure, and it contains secret and sensitive information. The MANET is use for designing specific type of applications. The providing security on that application are one of the major tasks for researchers. In this paper we observe the network vulnerabilities of a pro-active routing protocol. An analyzing attack on optimized link state routing (OLSR) protocol which is proactive, we propose a reputation base mechanism for prevention attacks. The mechanism is useful for securing the OLSR protocol against the denial of service attack (i.e. node isolation attack). Our mechanism is capable of finding whether a node is presenting correct network topology information or not by confirming its HELLO message. The experimental simulation results show the protocol is able to achieve routing security mechanism with increasing throughput, packet delivery frequency and control overhead. Our proposed mechanism is light weight because the protocol doesn´t include with high computational complexity for securing OLSR protocol against the node isolation attacks in MANETs. This mechanism brings few modifications and still compatible with the OLSR protocol. In order to evaluate network parameters by using network simulator (NS-2) tool.