Virtualization and Distribution of the BGP Control Plane

L'Internet est organisé sous la forme d'une multitude de réseaux appelés Systèmes Autonomes (AS). Le Border Gateway Protocol (BGP) est le langage commun qui permet à ces domaines administratifs de s'interconnecter. Grâce à BGP, deux utilisateurs situés n'importe où dans le monde peuvent communiquer, car ce protocole est responsable de la propagation des messages de routage entre tous les réseaux voisins. Afin de répondre aux nouvelles exigences, BGP a dû s'améliorer et évoluer à travers des extensions fréquentes et de nouvelles architectures. Dans la version d'origine, il était indispensable que chaque routeur maintienne une session avec tous les autres routeurs du réseau. Cette contrainte a soulevé des problèmes de scalabilité, puisque le maillage complet des sessions BGP internes (iBGP) était devenu difficile à réaliser dans les grands réseaux. Pour couvrir ce besoin de connectivité, les opérateurs de réseaux font appel à la réflection de routes (RR) et aux confédérations. Mais si elles résolvent un problème de scalabilité, ces deux solutions ont soulevé des nouveaux défis car elles sont accompagnées de multiples défauts; la perte de diversité des routes candidates au processus de sélection BGP ou des anomalies comme par exemple des oscillations de routage, des déflections et des boucles en font partie. Les travaux menés dans cette thèse se concentrent sur oBGP, une nouvelle architecture pour redistribuer les routes externes à l'intérieur d'un AS. `A la place des classiques sessions iBGP, un réseau de type overlay est responsable (I) de l'´echange d'informations de routage avec les autres AS, (II) du stockage distribué des routes internes et externes, (III) de l'application de la politique de routage au niveau de l'AS et (IV) du calcul et de la redistribution des meilleures routes vers les destinations de l'Internet pour tous les routeurs clients présents dans l'AS. ABSTRACT : The Internet is organized as a collection of networks called Autonomous Systems (ASes). The Border Gateway Protocol (BGP) is the glue that connects these administrative domains. Communication is thus possible between users worldwide and each network is responsible of sharing reachability information to peers through BGP. Protocol extensions are periodically added because the intended use and design of BGP no longer fit the current demands. Scalability concerns make the required internal BGP (iBGP) full mesh difficult to achieve in today's large networks and therefore network operators resort to confederations or Route Reflectors (RRs) to achieve full connectivity. These two options come with a set of flaws of their own such as route diversity loss, persistent routing oscillations, deflections, forwarding loops etc. In this dissertation we present oBGP, a new architecture for the redistribution of external routes inside an AS. Instead of relying on the usual statically configured set of iBGP sessions, we propose to use an overlay of routing instances that are collectively responsible for (I) the exchange of routes with other ASes, (II) the storage of internal and external routes, (III) the storage of the entire routing policy configuration of the AS and (IV) the computation and redistribution of the best routes towards Internet destinations to each client router in the AS

A pragmatic approach toward securing inter-domain routing

Internet security poses complex challenges at different levels, where even the basic requirement of availability of Internet connectivity becomes a conundrum sometimes. Recent Internet service disruption events have made the vulnerability of the Internet apparent, and exposed the current limitations of Internet security measures as well. Usually, the main cause of such incidents, even in the presence of the security measures proposed so far, is the unintended or intended exploitation of the loop holes in the protocols that govern the Internet. In this thesis, we focus on the security of two different protocols that were conceived with little or no security mechanisms but play a key role both in the present and the future of the Internet, namely the Border Gateway Protocol (BGP) and the Locator Identifier Separation Protocol (LISP). The BGP protocol, being the de-facto inter-domain routing protocol in the Internet, plays a crucial role in current communications. Due to lack of any intrinsic security mechanism, it is prone to a number of vulnerabilities that can result in partial paralysis of the Internet. In light of this, numerous security strategies were proposed but none of them were pragmatic enough to be widely accepted and only minor security tweaks have found the pathway to be adopted. Even the recent IETF Secure Inter-Domain Routing (SIDR) Working Group (WG) efforts including, the Resource Public Key Infrastructure (RPKI), Route Origin authorizations (ROAs), and BGP Security (BGPSEC) do not address the policy related security issues, such as Route Leaks (RL). Route leaks occur due to violation of the export routing policies among the Autonomous Systems (ASes). Route leaks not only have the potential to cause large scale Internet service disruptions but can result in traffic hijacking as well. In this part of the thesis, we examine the route leak problem and propose pragmatic security methodologies which a) require no changes to the BGP protocol, b) are neither dependent on third party information nor on third party security infrastructure, and c) are self-beneficial regardless of their adoption by other players. Our main contributions in this part of the thesis include a) a theoretical framework, which, under realistic assumptions, enables a domain to autonomously determine if a particular received route advertisement corresponds to a route leak, and b) three incremental detection techniques, namely Cross-Path (CP), Benign Fool Back (BFB), and Reverse Benign Fool Back (R-BFB). Our strength resides in the fact that these detection techniques solely require the analytical usage of in-house control-plane, data-plane and direct neighbor relationships information. We evaluate the performance of the three proposed route leak detection techniques both through real-time experiments as well as using simulations at large scale. Our results show that the proposed detection techniques achieve high success rates for countering route leaks in different scenarios. The motivation behind LISP protocol has shifted over time from solving routing scalability issues in the core Internet to a set of vital use cases for which LISP stands as a technology enabler. The IETF's LISP WG has recently started to work toward securing LISP, but the protocol still lacks end-to-end mechanisms for securing the overall registration process on the mapping system ensuring RLOC authorization and EID authorization. As a result LISP is unprotected against different attacks, such as RLOC spoofing, which can cripple even its basic functionality. For that purpose, in this part of the thesis we address the above mentioned issues and propose practical solutions that counter them. Our solutions take advantage of the low technological inertia of the LISP protocol. The changes proposed for the LISP protocol and the utilization of existing security infrastructure in our solutions enable resource authorizations and lay the foundation for the needed end-to-end security

Bioinspired metaheuristic algorithms for global optimization

This paper presents concise comparison study of newly developed bioinspired algorithms for global optimization problems. Three different metaheuristic techniques, namely Accelerated Particle Swarm Optimization (APSO), Firefly Algorithm (FA), and Grey Wolf Optimizer (GWO) are investigated and implemented in Matlab environment. These methods are compared on four unimodal and multimodal nonlinear functions in order to find global optimum values. Computational results indicate that GWO outperforms other intelligent techniques, and that all aforementioned algorithms can be successfully used for optimization of continuous functions

Experimental Evaluation of Growing and Pruning Hyper Basis Function Neural Networks Trained with Extended Information Filter

In this paper we test Extended Information Filter (EIF) for sequential training of Hyper Basis Function Neural Networks with growing and pruning ability (HBF-GP). The HBF neuron allows different scaling of input dimensions to provide better generalization property when dealing with complex nonlinear problems in engineering practice. The main intuition behind HBF is in generalization of Gaussian type of neuron that applies Mahalanobis-like distance as a distance metrics between input training sample and prototype vector. We exploit concept of neuron’s significance and allow growing and pruning of HBF neurons during sequential learning process. From engineer’s perspective, EIF is attractive for training of neural networks because it allows a designer to have scarce initial knowledge of the system/problem. Extensive experimental study shows that HBF neural network trained with EIF achieves same prediction error and compactness of network topology when compared to EKF, but without the need to know initial state uncertainty, which is its main advantage over EKF