Fault-Tolerant Software-Defined Networking (SDN) Design for Mitigating Control Plane Attacks

Software-Defined Networking (SDN) has transformed network management by separating the control plane from the data plane, enabling centralized control, programmability, and flexibility. However, this architectural paradigm introduces significant security concerns because the SDN controller becomes a critical point of failure and a primary target for cyberattacks. Control plane attacks such as Distributed Denial of Service (DDoS), controller hijacking, flow rule poisoning, and Byzantine failures can severely degrade network performance and availability. This study proposes a fault-tolerant SDN architecture designed to enhance control plane resilience against malicious attacks and operational failures. The proposed framework integrates distributed multi-controller deployment, Byzantine Fault Tolerance (BFT), intrusion detection mechanisms, secure communication protocols, and automated failover strategies. Reliability and availability models are developed to evaluate system performance under attack conditions. The architecture aims to improve network survivability, reduce downtime, and maintain consistent policy enforcement even in the presence of compromised controllers. The study contributes a comprehensive framework for building secure and resilient SDN infrastructures capable of supporting modern enterprise and critical infrastructure networks.