Biblio

Using Software-defined Networks in wide area (SDN-WAN) has been strongly emerging in the past years. Due to scalability and economical reasons, SDN-WAN mostly uses an in-band control mechanism, which implies that control and data sharing the same critical physical links. However, the in-band control and centralized control architecture can be exploited by attackers to launch distributed denial of service (DDoS) on SDN control plane by flooding the shared links and/or the Open flow agents. Therefore, constructing a resilient software designed network requires dynamic isolation and distribution of the control flow to minimize damage and significantly increase attack cost. Existing solutions fall short to address this challenge because they require expensive extra dedicated resources or changes in OpenFlow protocol. In this paper, we propose a moving target technique called REsilient COntrol Network architecture (ReCON) that uses the same SDN network resources to defend SDN control plane dynamically against the DDoS attacks. ReCON essentially, (1) minimizes the sharing of critical resources among data and control traffic, and (2) elastically increases the limited capacity of the software control agents on-demand by dynamically using the under-utilized resources from within the same SDN network. To implement a practical solution, we formalize ReCON as a constraints satisfaction problem using Satisfiability Modulo Theory (SMT) to guarantee a correct-by-construction control plan placement that can handle dynamic network conditions.

The deterministic nature of existing routing protocols has resulted into an ossified Internet with static and predictable network routes. This gives persistent attackers (e.g. eavesdroppers and DDoS attackers) plenty of time to study the network and identify the vulnerable (critical) links to plan devastating and stealthy attacks. Recently, Moving Target Defense (MTD) based approaches have been proposed to to defend against DoS attacks. However, MTD based approaches for route mutation are oriented towards re-configuring the parameters in Local Area Networks (LANs), and do not provide any protection against infrastructure level attacks, which inherently limits their use for mission critical services over the Internet infrastructure. To cope with these issues, we extend the current routing architecture to consider end-hosts as routing elements, and present a formal method based agile defense mechanism to embed resiliency in the existing cyber infrastructure. The major contributions of this paper include: (1) formalization of efficient and resilient End to End (E2E) reachability problem as a constraint satisfaction problem, which identifies the potential end-hosts to reach a destination while satisfying resilience and QoS constraints, (2) design and implementation of a novel decentralized End Point Route Mutation (EPRM) protocol, and (3) design and implementation of planning algorithm to minimize the overlap between multiple flows, for the sake of maximizing the agility in the system. Our PlanetLab based implementation and evaluation validates the correctness, effectiveness and scalability of the proposed approach.