Mobile Adhoc Networks (MANETs) are networks of mobile nodes which have limited resources in terms of processing power, memory and battery life. The traffic to the destination nodes which are beyond the range of source nodes are routed by the intermediate nodes. The routing in the MANETs is different from conventional infrastructure network since the nodes not only act as end devices but also act as routers. Owing to the resource constraint of the nodes the routing protocols for MANETs have to be light weight and assume a trusted environment.
The absence of any infrastructure for security and ever changing topology of the network makes the routing protocols vulnerable to variety of attacks. These attacks may lead to either misdirection of data traffic or denial of services. The mitigation techniques to combat the attacks in MANETs have to work under severe constraints, and therefore it is imperative to study the vulnerabilities of the routing protocols and methods of launching the attack in detail. This paper attempts to do the same and has reviewed some current literature on mitigation of the routing attacks.