Research on DDoS Defense Technologies in Cloud Environments and Software-Defined Networking Architectures

With advances in cloud computing, big data, and mobile Internet technologies, the demand for unified network management, maintenance, and security has surged. Software-Defined Networking (SDN) has rapidly developed to meet these needs by decoupling the control and data planes, enabling centralized management and programmability. These features offer novel approaches for mitigating Denial-of-Service (DoS) attacks. In this paper, we investigate DoS/DDoS threats in SDN networks and cloud environments, propose a novel DoS attack targeting SDN controllers, and introduce an OpenFlow-based detection and defense scheme for conventional host-targeted DoS attacks. We validate the effectiveness of these schemes on a simulation platform. Experimental results show that the proposed attack can exhaust the controller's resources, successfully disrupting normal operation. The detection scheme accurately identifies Land attacks on hosts, achieving high detection accuracy, processing efficiency, and very low detection latency. The defense scheme enables rapid mitigation of Land attacks, as confirmed by the SEER tool. Additionally, the cloud-based DDoS defense scheme effectively filters attack traffic and maintains stable resource utilization under attack.