26 research outputs found

    Commentary on Inter-Domain Routing in the Internet

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    Predicting Global Internet Instability Caused by Worms using Neural Networks

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    Student Number : 9607275H - MSc dissertation - School of Electrical and Information Engineering - Faculty of Engineering and the Built EnvironmentInternet worms are capable of quickly propagating by exploiting vulnerabilities of hosts that have access to the Internet. Once a computer has been infected, the worms have access to sensitive information on the computer, and are able to corrupt or retransmit this information. This dissertation describes a method of predicting Internet instability due to the presence of a worm on the Internet, using data currently available from global Internet routers. The work is based on previous research which has indicated a link between the increase in the number of Border Gateway Protocol (BGP) routing messages and global Internet instability. The type of system used to provide the prediction is known as an autoencoder. This is a specialised type of neural network, which is able to provide a degree of novelty for inputs. The autoencoder is trained to recognise “normal” data, and therefore provides a high novelty output for inputs dissimilar to the normal data. The BGP Update routing messages sent between routers were used as the only inputs to the autoencoder. These intra-router messages provide route availability information, and inform neighbouring routers of any route changes. The outputs from the network were shown to help provide an early warning mechanism for the presence of a worm. An alternative method for detecting instability is a rule-based system, which generates alarms if the number of certain BGP routing messages exceeds a prespecified threshold. This project compared the autoencoder to a simple rule-based system. The results showed that the autoencoder provided a better prediction and was less complex for a network administrator to configure. Although the correlation between the number of BGP Updates and global Internet instability has been shown previously, this work presents the first known application of a neural network to predict the instability using this correlation. A system based on this strategy has the potential to reduce the damage done by a worm’s propagation and payload, by providing an automated means of detection that is faster than that of a human

    BGP-XM: BGP eXtended Multipath for Transit Autonomous Systems

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    Multipath interdomain routing has been proposed to enable flexible traffic engineering for transit Autonomos Systems (ASes). Yet, there is a lack of solutions providing maximal path diversity and backwards compatibility at the same time. The BGP-XM (Border Gateway Protocol-eXtended Multipath) extension presented in this paper is a complete and flexible approach to solve many of the limitations of previous BGP multipath solutions. ASes can benefit from multipath capabilities starting with a single upgraded router, and without any coordination with other ASes. BGP-XM defines an algorithm to merge into regular BGP updates information from paths which may even traverse different ASes. This algorithm can be combined with different multipath selection algorithms, such as the K-BESTRO (K-Best Route Optimizer) tunable selection algorithm proposed in this paper. A stability analysis and stable policy guidelines are provided. The performance evaluation of BGP-XM, running over an Internet-like topology, shows that high path diversity can be achieved even for limited deployments of the multipath mechanism. Further results for large-scale deployments reveal that the extension is suitable for large deployment since it shows a low impact in the AS path length and in the routing table size

    Measuring Effectiveness of Address Schemes for AS-level Graphs

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    This dissertation presents measures of efficiency and locality for Internet addressing schemes. Historically speaking, many issues, faced by the Internet, have been solved just in time, to make the Internet just work~\cite{justWork}. Consensus, however, has been reached that today\u27s Internet routing and addressing system is facing serious scaling problems: multi-homing which causes finer granularity of routing policies and finer control to realize various traffic engineering requirements, an increased demand for provider-independent prefix allocations which injects unaggregatable prefixes into the Default Free Zone (DFZ) routing table, and ever-increasing Internet user population and mobile edge devices. As a result, the DFZ routing table is again growing at an exponential rate. Hierarchical, topology-based addressing has long been considered crucial to routing and forwarding scalability. Recently, however, a number of research efforts are considering alternatives to this traditional approach. With the goal of informing such research, we investigated the efficiency of address assignment in the existing (IPv4) Internet. In particular, we ask the question: ``how can we measure the locality of an address scheme given an input AS-level graph?\u27\u27 To do so, we first define a notion of efficiency or locality based on the average number of bit-hops required to advertize all prefixes in the Internet. In order to quantify how far from ``optimal the current Internet is, we assign prefixes to ASes ``from scratch in a manner that preserves observed semantics, using three increasingly strict definitions of equivalence. Next we propose another metric that in some sense quantifies the ``efficiency of the labeling and is independent of forwarding/routing mechanisms. We validate the effectiveness of the metric by applying it to a series of address schemes with increasing randomness given an input AS-level graph. After that we apply the metric to the current Internet address scheme across years and compare the results with those of compact routing schemes

    Strategies for internet route control: past, present and future

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    Uno de los problemas más complejos en redes de computadores es el de proporcionar garantías de calidad y confiabilidad a las comunicaciones de datos entre entidades que se encuentran en dominios distintos. Esto se debe a un amplio conjunto de razones -- las cuales serán analizadas en detalle en esta tesis -- pero de manera muy breve podemos destacar: i) la limitada flexibilidad que presenta el modelo actual de encaminamiento inter-dominio en materia de ingeniería de tráfico; ii) la naturaleza distribuida y potencialmente antagónica de las políticas de encaminamiento, las cuales son administradas individualmente y sin coordinación por cada dominio en Internet; y iii) las carencias del protocolo de encaminamiento inter-dominio utilizado en Internet, denominado BGP (Border Gateway Protocol).El objetivo de esta tesis, es precisamente el estudio y propuesta de soluciones que permitan mejorar drásticamente la calidad y confiabilidad de las comunicaciones de datos en redes conformadas por múltiples dominios.Una de las principales herramientas para lograr este fin, es tomar el control de las decisiones de encaminamiento y las posibles acciones de ingeniería de tráfico llevadas a cabo en cada dominio. Por este motivo, esta tesis explora distintas estrategias de como controlar en forma precisa y eficiente, tanto el encaminamiento como las decisiones de ingeniería de tráfico en Internet. En la actualidad este control reside principalmente en BGP, el cual como indicamos anteriormente, es uno de los principales responsables de las limitantes existentes. El paso natural sería reemplazar a BGP, pero su despliegue actual y su reconocida operatividad en muchos otros aspectos, resultan claros indicadores de que su sustitución (ó su posible evolución) será probablemente gradual. En este escenario, esta tesis propone analizar y contribuir con nuevas estrategias en materia de control de encaminamiento e ingeniería de tráfico inter-dominio en tres marcos temporales distintos: i) en la actualidad en redes IP; ii) en un futuro cercano en redes IP/MPLS (MultiProtocol Label Switching); y iii) a largo plazo en redes ópticas, modelando así una evolución progresiva y realista, facilitando el reemplazo gradual de BGP.Más concretamente, este trabajo analiza y contribuye mediante: - La propuesta de estrategias incrementales basadas en el Control Inteligente de Rutas (Intelligent Route Control, IRC) para redes IP en la actualidad. Las estrategias propuestas en este caso son de carácter incremental en el sentido de que interaccionan con BGP, solucionando varias de las carencias que éste presenta sin llegar a proponer aún su reemplazo. - La propuesta de estrategias concurrentes basadas en extender el concepto del PCE (Path Computation Element) proveniente del IETF (Internet Engineering Task Force) para redes IP/MPLS en un futuro cercano. Las estrategias propuestas en este caso son de carácter concurrente en el sentido de que no interaccionan con BGP y pueden ser desplegadas en forma paralela. En este caso, BGP continúa controlando el encaminamiento y las acciones de ingeniería de tráfico inter-dominio del tráfico IP, pero el control del tráfico IP/MPLS se efectúa en forma independiente de BGP mediante los PCEs.- La propuesta de estrategias que reemplazan completamente a BGP basadas en la incorporación de un nuevo agente de control, al cual denominamos IDRA (Inter-Domain Routing Agent). Estos agentes proporcionan un plano de control dedicado, físicamente independiente del plano de datos, y con gran capacidad computacional para las futuras redes ópticas multi-dominio.Los resultados expuestos aquí validan la efectividad de las estrategias propuestas, las cuales mejoran significativamente tanto la concepción como la performance de las actuales soluciones en el área de Control Inteligente de Rutas, del esperado PCE en un futuro cercano, y de las propuestas existentes para extender BGP al área de redes ópticas.One of the most complex problems in computer networks is how to provide guaranteed performance and reliability to the communications carried out between nodes located in different domains. This is due to several reasons -- which will be analyzed in detail in this thesis -- but in brief, this is mostly due to: i) the limited capabilities of the current inter-domain routing model in terms of Traffic Engineering (TE); ii) the distributed and potentially conflicting nature of policy-based routing, where routing policies are managed independently and without coordination among domains; and iii) the clear limitations of the inter-domain routing protocol, namely, the Border Gateway Protocol (BGP). The goal of this thesis is precisely to study and propose solutions allowing to drastically improve the performance and reliability of inter-domain communications. One of the most important tools to achieve this goal, is to control the routing and TE decisions performed by routing domains. Therefore, this thesis explores different strategies on how to control such decisions in a highly efficient and accurate way. At present, this control mostly resides in BGP, but as mentioned above, BGP is in fact one of the main causes of the existing limitations. The natural next-step would be to replace BGP, but the large installed base at present together with its recognized effectiveness in other aspects, are clear indicators that its replacement (or its possible evolution) will probably be gradually put into practice.In this framework, this thesis proposes to to study and contribute with novel strategies to control the routing and TE decisions of domains in three different time frames: i) at present in IP multi-domain networks; ii) in the near-future in IP/MPLS (MultiProtocol Label Switching) multi- domain networks; and iii) in the future optical Internet, modeling in this way a realistic and progressive evolution, facilitating the gradual replacement of BGP.More specifically, the contributions in this thesis can be summarized as follows. - We start by proposing incremental strategies based on Intelligent Route Control (IRC) solutions for IP networks. The strategies proposed in this case are incremental in the sense that they interact with BGP, and tackle several of its well-known limitations. - Then, we propose a set of concurrent route control strategies for MPLS networks, based on broadening the concept of the Path Computation Element (PCE) coming from the IETF (Internet Engineering Task Force). Our strategies are concurrent in the sense that they do not interact directly with BGP, and they can be deployed in parallel. In this case, BGP still controlls the routing and TE actions concerning regular IP-based traffic, but not how IP/MPLS paths are routed and controlled. These are handled independently by the PCEs.- We end with the proposal of a set of route control strategies for multi-domain optical networks, where BGP has been completely replaced. These strategies are supported by the introduction of a new route control element, which we named Inter-Domain Routing Agent (IDRA). These IDRAs provide a dedicated control plane, i.e., physically independent from the data plane, and with high computational capacity for future optical networks.The results obtained validate the effectiveness of the strategies proposed here, and confirm that our proposals significantly improve both the conception and performance of the current IRC solutions, the expected PCE in the near-future, as well as the existing proposals about the optical extension of BGP.Postprint (published version

    CHASING THE UNKNOWN: A PREDICTIVE MODEL TO DEMYSTIFY BGP COMMUNITY SEMANTICS

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    The Border Gateway Protocol (BGP) specifies an optional communities attribute for traffic engineering, route manipulation, remotely-triggered blackholing, and other services. However, communities have neither unifying semantics nor cryptographic protections and often propagate much farther than intended. Consequently, Autonomous System (AS) operators are free to define their own community values. This research is a proof-of-concept for a machine learning approach to prediction of community semantics; it attempts a quantitative measurement of semantic predictability between different AS semantic schemata. Ground-truth community semantics data were collated and manually labeled according to a unified taxonomy of community services. Various classification algorithms, including a feed-forward Multi-Layer Perceptron and a Random Forest, were used as the estimator for a One-vs-All multi-class model and trained according to a feature set engineered from this data. The best model's performance on the test set indicates as much as 89.15% of these semantics can be accurately predicted according to a proposed standard taxonomy of community services. This model was additionally applied to historical BGP data from various route collectors to estimate the taxonomic distribution of communities transiting the control plane.http://archive.org/details/chasingtheunknow1094566047Outstanding ThesisCivilian, CyberCorps - Scholarship For ServiceApproved for public release. distribution is unlimite

    Performance Evaluation of Distributed Security Protocols Using Discrete Event Simulation

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    The Border Gateway Protocol (BGP) that manages inter-domain routing on the Internet lacks security. Protective measures using public key cryptography introduce complexities and costs. To support authentication and other security functionality in large networks, we need public key infrastructures (PKIs). Protocols that distribute and validate certificates introduce additional complexities and costs. The certification path building algorithm that helps users establish trust on certificates in the distributed network environment is particularly complicated. Neither routing security nor PKI come for free. Prior to this work, the research study on performance issues of these large-scale distributed security systems was minimal. In this thesis, we evaluate the performance of BGP security protocols and PKI systems. We answer the questions about how the performance affects protocol behaviors and how we can improve the efficiency of these distributed protocols to bring them one step closer to reality. The complexity of the Internet makes an analytical approach difficult; and the scale of Internet makes empirical approaches also unworkable. Consequently, we take the approach of simulation. We have built the simulation frameworks to model a number of BGP security protocols and the PKI system. We have identified performance problems of Secure BGP (S-BGP), a primary BGP security protocol, and proposed and evaluated Signature Amortization (S-A) and Aggregated Path Authentication (APA) schemes that significantly improve efficiency of S-BGP without compromising security. We have also built a simulation framework for general PKI systems and evaluated certification path building algorithms, a critical part of establishing trust in Internet-scale PKI, and used this framework to improve algorithm performance

    Virtualization and Distribution of the BGP Control Plane

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    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
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