摘要
A Mobile ad hoc network (MANET) is self organizing, decentralized and infrastructure less wireless network. The successful transmission of data packet is depends on the cooperation of each node in the network. These types of network don’t have permanent base station, so each node in the network acts as a router. Due to openness, decentralized, self organizing nature of MANET, it is vulnerable to various attacks. So security is the main concern in MANET. In this paper, we considered two attacks; Vampire and DDoS attacks. The Vampire attack is not any protocol specific. Single Vampire attack can increase the network-wide energy usage. DDoS attacks exhaust the resources available to a network. Both the attacks drain the energy of nodes. Here, we discuss method to mitigate these attacks.