Design And Implementation Of The Virtual And Reality Network System Based On NS-3

With the development of the network and the frequent occurrence of the security incidents, the network experiment and research have become more and more complex, the traditional research is based on the physical experiment bed and the network simulation. However, there is a problem of small scale and high cost in physical test bed, and the authenticity of network simulation can not be guaranteed so the both can not truly meet the needs of network experiments. Therefore, how to construct a real and effective experimental environment has become a problem to be solved urgently in the field of network security.Aiming at this problem, this paper proposes a system combining the virtual network and real network which is based on NS-3, establishing a virtual and actual docking model between physical network and simulated network,building the network experimental environment of the virtual and the real communication,to solve the disadvantages of high cost in physical test-bed and the low authenticity in network simulation.First of all, the network topology description is completed, the network elements in the actual network topology are defined, and the network topology is normalized to form a unified network environment interface. At the same time, the software automatic deployment function is provided to realize the automatic installation and deployment of the experimental system and experimental scene.Secondly, this paper designs and implements the communication model between the actual situation and the simulated situation, using the v irtual network card bridging technology,the algorithm to monitor message based on polling mechanism(PMA),and the algorithm of filtering the Ethernet packet(EFA) to complete the communication between physical network and simulation network boundary.Thirdly, this paper uses the improved routing algorithm based on breadth-first search(BFSIA) to complete the entire network topology routing calculation and uses ip route to complete the exterior routing configuration and NS-3 static routing API to complete internal routing configuration, to realize the physical network and the whole simulation network connectivity.Finally, in order to verify the actual communication model is feasible, the current mainstream IRC botnet of sending spam is modeled,designed and implented in NS-3 simulation network. The test shows that the real time communication between the physical network and the simulation network can be realized, the network environment which combines the simulation network with physical network can be constructed. Through the simulation experiment of ping and botnet spam, the real time and availability of the virtual and actual environment is verified.In addition, the system has the function of real-time monitoring of network traffic,to monitor the change of the experimental network traffic.