摘要：Problem statement: An important and challenging problem is that of tracing DOS/DDOS attack source. IP traceback is the process of identifying the actual source(s) of attack packets, So that the attackers can be held accountable as also in mitigating them, either by isolating the attack sources or by filtering packets for away from the victim. Several IP traceback schemes have been proposed to solve this problem. Among many IP traceback schemes, a recent development was Directed Geographical Traceback (DGT). Though multidirectional two-dimensional DGT schemes were available, in the real scenario, three dimensional, Multidirectional DGT has potential applications. Approach: The Direction Ratio Algorithm (DRA) has the limitation of the impossibility of ensuring sufficient unused space in the packet header for the complete Direction Ratio List (DRL) especially when the length of the path is not known apriori. To overcome this, DRSA was proposed. The methods used in DRSA were random sampling methods, where the sufficient numbers of samples were drawn; one can reconstruct the path of the attack packets and trace the attack source. Results : In this study those limitation had been overcome using Direction Ratio Sampling Algorithm (DRSA) which works well for 3-dimensional, multi-directional, geographical IP traceback. This approach enables the attack path reconstruction was easily possible and hence a victim can typically reconstruct the path after receiving 75 packets from the attacker. This same algorithm can efficiently discern multiple attacks. When attackers from different sources produce disjoint edges in the tree structure of reconstruction, the number of packets needed to reconstruct each path is independent of other paths. Conclusion: DRSA was found to be a robust scheme of attack path reconstruction in Geographical traceback.
关键词：DOS (Distributed Denial of Service); DGT (Directional Geographical traceback); 3DMDGT (Three dimensional; Multi-Directional Geographical traceback); DRA (Direction Ratio Algorithm); DRSA (Direction Ratio Sampling Algorithm)
