Mobile ad-hoc network is the network comprised of wireless nodes. It has basically no infrastructure i.e. the connections are established without any centralized administration. A Mobile Ad-hoc NETwork (MANET) is a spontaneous network that can be established with no fixed infrastructure. Aim of Denial of Service (DoS) attack is to overload the server's bandwidth and other resources. A DDoS attack is a severe form of DOS which uses multiple machines to prevent the legitimate use of a service. A bandwidth depletion and resource depletion attack is designed to flood the victim network with unwanted traffic that prevents legitimate traffic from reaching the victim system.