Performance assessment of OLSR protocol under routing attacks

Routing is one of the most important challenges regarding mobile ad hoc networks (MANETs). Having no fixed infrastructure along with frequent network topology changes, as a result of nodes mobility, necessitate routing protocols to operate under cooperation of all network nodes. Lack of cooperation in routing can lead to performance reduction and even network denial of service. Uncooperative behavior of nodes can be performed selfishly by refraining from forwarding data packets or, in a more advanced class, maliciously in the form of an attack against the network. One of the most famous, challenging, and destructive routing attacks in MANETs, which can dramatically reduce network performance, is known as Black-hole attack. Black hole attack operates based upon two different phases. The first phase consists of absorbing a considerable amount of network traffic towards attacker node, and the second one is dropping received data packets. In optimized link state routing (OLSR) protocol, a well-known proactive routing algorithm for MANETs, Black hole attack can be implemented in different methods. The objective of this paper is to evaluate effects of different Black hole implementations as well as various selfish behaviors on OLSR based MANETs. Assessment of network parameters has been carried out using Network Simulator (NS-2). Simulation results represent that a special implementation of Black hole attack, which is named as TC-HELLO-Black-Hole and considered in this paper for the first time, is more devastating compared to other implementations and selfish nodes. Furthermore, such attack lessens routing overhead compared to basic OLSR.