Applying Formal Methods to Networking: Theory, Techniques and Applications

Despite its great importance, modern network infrastructure is remarkable for the lack of rigor in its engineering. The Internet which began as a research experiment was never designed to handle the users and applications it hosts today. The lack of formalization of the Internet architecture meant limited abstractions and modularity, especially for the control and management planes, thus requiring for every new need a new protocol built from scratch. This led to an unwieldy ossified Internet architecture resistant to any attempts at formal verification, and an Internet culture where expediency and pragmatism are favored over formal correctness. Fortunately, recent work in the space of clean slate Internet design---especially, the software defined networking (SDN) paradigm---offers the Internet community another chance to develop the right kind of architecture and abstractions. This has also led to a great resurgence in interest of applying formal methods to specification, verification, and synthesis of networking protocols and applications. In this paper, we present a self-contained tutorial of the formidable amount of work that has been done in formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial

Routing-Verification-as-a-Service (RVaaS): Trustworthy Routing Despite Insecure Providers

Computer networks today typically do not provide any mechanisms to the users to learn, in a reliable manner, which paths have (and have not) been taken by their packets. Rather, it seems inevitable that as soon as a packet leaves the network card, the user is forced to trust the network provider to forward the packets as expected or agreed upon. This can be undesirable, especially in the light of today's trend toward more programmable networks: after a successful cyber attack on the network management system or Software-Defined Network (SDN) control plane, an adversary in principle has complete control over the network. This paper presents a low-cost and efficient solution to detect misbehaviors and ensure trustworthy routing over untrusted or insecure providers, in particular providers whose management system or control plane has been compromised (e.g., using a cyber attack). We propose Routing-Verification-as-a-Service (RVaaS): RVaaS offers clients a flexible interface to query information relevant to their traffic, while respecting the autonomy of the network provider. RVaaS leverages key features of OpenFlow-based SDNs to combine (passive and active) configuration monitoring, logical data plane verification and actual in-band tests, in a novel manner

A Survey of Software-Defined Networking: Past, Present, and Future of Programmable Networks

accepted in IEEE Communications Surveys & TutorialsInternational audienceThe idea of programmable networks has recently re-gained considerable momentum due to the emergence of the Software-Defined Networking (SDN) paradigm. SDN, often referred to as a ''radical new idea in networking'', promises to dramatically simplify network management and enable innovation through network programmability. This paper surveys the state-of-the-art in programmable networks with an emphasis on SDN. We provide a historic perspective of programmable networks from early ideas to recent developments. Then we present the SDN architecture and the OpenFlow standard in particular, discuss current alternatives for implementation and testing of SDN-based protocols and services, examine current and future SDN applications, and explore promising research directions based on the SDN paradigm

Scenario based security evaluation: Generic OpenFlow network

Demand for network programmability was recognized when development of protocolsslowed down due to network inflexibilities in 1980s. Research speeded up andmany proposals were made to solve architectural issues during 2000s. Academicworld put up an initiative to build up new programmable network architecturelater 2000s. OpenFlow was born.In modern public network infrastructures the security of the network architectureis crucial to archive data confidentiality, integrity and authenticity, yet high availability.Many studies have shown that there are many security vulnerabilities andissues on current OpenFlow implementations and even in OpenFlow specificationitself. Many proposals have been made to enhance these known issues. In thisresearch, the scenario based security evaluation of the generic OpenFlow networkarchitecture was carried out using technology publications and literature. Thesecurity evaluation framework was used in security assessment.Proposed risk mitigation patterns were found to be effective on most of the casesfor all 13 identified and evaluated scenarios. Lack of mandatory encryption andauthentication in OpenFlow control channel were most critical risks on generallevel. OpenFlow specification should provide clear guidance how this should beimplemented to guarantee inter-operability between different vendors. Short termsolution is to use IPSec. Second critical issue was that bugs and vulnerabilitiesin OpenFlow controller and switch software are causing major risks for security.Proper quality assurance process, testing methods and evaluation are needed toenhance security on all phases of the software production.Current OpenFlow implementations are suffering poor security. Tolerable levelcan be reached by utilizing small enhancements. There are still many areas whichneed to be researched to archive solid foundation for software defined networks ofthe future

Performance analysis and optimization in software defined networks

In this thesis, candidate addressed two interesting and practical problems: performance analysis and optimization for (1) controllers and (2) switches in Software-Defined Networks. Candidate developed a queueing theory based optimization framework in a distributed SDN architecture that provides QoS-guaranteed flow-balancing in pro-active operations of SDN controllers. Further, candidate developed an analytical model for modeling SDN switches. The results in this thesis will contribute to the design and development of future Software-Defined Networks.<br /

Software defined networking for radio telescopes: a case study on the applicability of SDN for MeerKAT

Scientific instruments like radio telescopes depend on high-performance networks for internal data exchange. The high bandwidth data exchange between the components of a radio telescope makes use of multicast networking. Complex multicast networks are hard to maintain and grow, and specific installations require modified network switches. This study evaluates Software Defined Networking (SDN) for use in the MeerKAT radio telescope to alleviate the management complexity and allow for a vendor-neutral implementation. The purpose of this dissertation is to verify that an SDN multicast network can produce suitable paths for data flow through the network and to see if such an implementation is easier to maintain and grow. There is little literature regarding SDN for radio telescope networks; however, there is considerable work where different aspects of SDN are discussed and demonstrated for video streaming. SDN with multicast for video streaming, although simpler, forms the background research. Considerable work was put into understanding and documenting the different aspects of a radio telescope affecting the data network. The telescope network controller generates the OpenFlow rules required by the SDN controller and is a new concept introduced in this work. The telescope network controller is fitted with two placement algorithms to demonstrate its flexibility. Both algorithms are suitable for the expected workload, but they produce very different traffic patterns. The two algorithms are not compared to one another, they were created to demonstrate the ease of adding domain specific knowledge to an SDN. The telescope network controller makes it easy to introduce and use new flow placement algorithms, thus making traffic engineering feasible for the radio telescope. Complex multicast networks are easier to maintain and grow with SDN. SDN allows customised packet forwarding rules typically unattainable with standard routing and other standard network protocols and implementations. A radio telescope with a software-defined data network is resilient, easier to maintain, vendor-neutral, and possesses advanced traffic engineering mechanisms