Securing Inter-Controller Communication in Distributed SDN Networks

Abstract

The adoption of Software-Defined Networking (SDN) has revolutionized network architecture by decoupling the control plane from the data plane, enabling centralized programmability and dynamic network management. However, as networks scale, the reliance on distributed SDN controllers becomes essential to ensure fault tolerance, performance, and geographical coverage. This shift introduces a critical security challenge: securing inter-controller communication across east-west interfaces. Unsecured communication channels between SDN controllers expose the network to a range of threats including spoofing, message tampering, and compromised trust models.
This paper investigates the architectural nuances and security requirements for inter-controller communication in distributed SDN environments. It presents a comprehensive threat analysis, critiques current security implementations, and proposes a robust framework that incorporates lightweight mutual authentication, integrity-preserving message exchange, and trust federation mechanisms. Through simulated testbed evaluations, the proposed approach demonstrates resilience against common attack vectors with minimal performance trade-offs. The findings contribute to ongoing efforts to strengthen SDN architectures against evolving cybersecurity threats, particularly in multi-domain and large-scale deployments.