Oriented Traceback For Manet Stable Topological Study

MANET (Mobile ad hoc networks) is a multi-hop temporary autonomous system and is made up of some mobile nodes equipped with wireless transmitter-receiver set. Each node in the network also acts as a router, forwarding data packets to other nodes. With unique features of decentralization and self-organization, MANET has always been studied in scientific research and given intense attention. The resource of MANET is rear and nodes can not be trusted, so MANET is particularly vulnerable to DDoS (Distributed Denial-of-Service) attack. In order to withstand DDoS attack, the traceback technologies is an important part of active defense system, is also a hot spot in domestic and foreign researchers.The dynamic topology change in MANET causes a great difficult for traceback. Even if the tracking speed is fast, once the network topology changes, tracking results may also be invalid. It will directly affect the effectiveness of follow-up defensive measures. Therefore, stable topology is the key to solving the problem. The thesis does some research on designing stable topology. The main work and the creative point illustrate the following aspects. 1,The thesis describes the research background, purpose and significance of MANET research, and then focuses on the characteristics and key technology issues for MANET. For the features of MANET, the thesis compares some typical routing protocols, analyses the limitation of the resource of MANET and that nodes can not be trusted resulting networks vulnerable to DDoS attacks, making deep research on both domestic and foreign traceback of DDoS attack in MANET.2,According to the dynamic topology of MANET, the thesis designs and realizes a new protocol IR-AODV (Identity Replace of AODV) which is based on Identity Replace and improved from the protocol of AODV. A new concept of logical topology is proposed from the perspective of topology stability. With constructing a temporary logical topology corresponds to physical topology in routing layer, the protocol of IR-AODV maintains the stability of logical topology by identity replacement. The final purpose is to track the attacker.3,This thesis suggests a new concept of stable time window. The concept is to verify the feasibility of tracking the attacker based the IR-AODV protocol, so that we can make appropriate follow-up defensive measures in the future.4,This thesis implements the protocol of IR-AODV and analyses the coding of AODV, and then simulates it by using Glomosim. The thesis also compares the stability of AODV and IR-AODV in such aspects of the packet delivery ratio, link replacement ratio successful replacement ratio of the same node and stable time window and so on. The simulation result shows that the traceback in the protocol of IR-AODV is feasible.