a novel Dynamic multi-Species Particle Swarm Optimization (DSPSO) algorithm based on food chain mechanism was proposed aiming at the problem that the basic Particle Swarm Optimization (PSO) algorithm is easy fall into local optimal solution when solving multimodal problems. Inspired by the natural ecosystem, a food chain mechanism and a reproduction mechanism were employed to keep the swarm diversity and good performance. In food chain mechanism, the swarm was divided into several sub-swarms, and each sub-swarm could prey on the others. The memory leader swarm was evolved and the less contributed particle was eliminated through predation, and then the new particle was generated through reproduction mechanism. The diversity was kept through the evaluation of the swarm, and the efficiency of the algorithm was enhanced through eliminating the misleading effect of the less contributed particles. In order to verify the effectiveness of the algorithm, ten benchmark problems including shifted problems and rotated problems were chose to test the performance of DSPSO. The experimental results show that DSPSO has a well optimizing performance. Compared with PSO algorithm, Local version Particle Swarm Optimization (LPSO) algorithm, Dynamic Multi-Swarm Particle Swarm Optimization (DMS-PSO) algorithm and Comprehensive Learning Particle Swarm Optimization (CLPSO) algorithm, DSPSO algorithm not only obtains more accurate solutions, but also has higher reliability.

IP address security is always a critical Internet security issue. As the transition from IPv4 to IPv6, multiple allocation modes of IP address, IPv6 translation techniques and IP spoofing increase the uncertainty of IP address of the host and the host has multiple IP addresses, which makes IP address resource more insecure. The emerging IPv6 home network, small enterprise network and campus network interconnect with traditional IPv4 network, which is typical and inevitable IPv6 translation scenario, and traditional IP traceback techniques cannot directly be applied to these scenarios. Therefore, this paper presented a new approach to solve IP traceback issue under these scenarios, which is able to go across the gateway that interconnects between IPv4 network and IPv6 network, and makes the destination network knowable for the source network. The traceback method guarantees the Internet fundamental resource safe.