A Mobile Ad-Hoc NETwork (MANET) is a temporary infrastructure less network, formed by a set of mobile hosts that dynamically establish their own network without relying on any central administration. Mobile ad hoc networking works properly only if the participating nodes cooperate in routing and forwarding. However, performing network functions consumes energy and other resources. To save its energy a node may behave selfishly and uses the forwarding service of other nodes without correctly forwarding packets for them. These nodes must be identified and excluded from the cooperative part of the network, as they only consume resources and don't contribute to the infrastructure. In MANET's routing misbehavior can severely degrade the performance at the routing layer.