Scaling the Internet Routing System Through Distributed Route Aggregation

The Internet consists of a large number of autonomous systems (ASes) that exchange routing information using the border gateway protocol (BGP). Each AS applies local policies for selecting routes and propagating routes to others, with important implications for the reliability and stability of the global system. In and of itself, BGP does not ensure that every pair of hosts can communicate. In addition, routing policies are not guaranteed be safe, and may cause protocol divergence. Backup routing is often used to increase the reliability of the network under link and router failures, at the possible expense of safety. This paper presents a general model for backup routing that increases network reliability while allowing each AS to apply local routing policies that are consistent with the commercial relationships it has with its neighbors. In addition, our model is inherently safe in the sense that the global system remains safe under any combination of link and router failures. Our model and the proof of inherent safety are cast in terms of the stable paths problem, a static formalism that captures the semantics of interdomain routing policies. Then, we describe how to realize our model in BGP with locally-implementable routing policies. To simplify the specification of local policies, we propose a new BGP attribute that conveys the avoidance level of a route. We also describe how to realize these policies without modification to BGP by using the BGP community attribute.

Examining the Jurisdictions of Internet Routes to Prevent Data Exfiltration

Despite years of research, the Internet still lacks a routing protocol with guaranteed termination. As is well-known, decentralization of routing decisions among the Autonomous Systems (ASes) that comprise the Internet may result in permanent oscillations of the state of its routing protocol — the Border Gateway Protocol (BGP). Some permanent oscillations are made from routing loops — the propagation of routing messages around the cycles of a network — that come back time and again. We discovered that the routing loop detection capability of BGP can be sharpened to predict which routing loops potentially recur and that the import policies can be adjusted to prevent the recurrence. The resulting protocol, named Self-Stable BGP (SS-BGP), is more stable than BGP. For the broad and common class of isotone routing policies, all permament oscillations are made from recurrent routing loops. For this class of routing policies, SS-BGP terminates. Our simulations with realistic Internet topologies and realistic variations of the Gao-Rexford (GR) inter-AS routing policies show that SS-BGP arrives at stable states at the expense of alterations in the import policies of only a handful of ASes.

The Internet consists of many self-administered and inter-connected Autonomous Systems (ASms). ASms exchange inter-AS routing information with each other via the Border Gateway Protocol (BGP). Neighboring BGP routers located in different ASms share their inter-AS routing information via external BGP (eBGP), whereas two routers in the same AS share their inter-AS routing information via internal BGP (iBGP). From the paths received from its peers, each BGP router chooses the best path based on routing policies chosen locally at its own AS. Conflicting policies between different ASms may cause divergence problems in eBGP, i.e., permanent oscillations in the chosen path to the destination. On the other hand, divergence problems may also occur in iBGP. This is caused by the interaction of route-reflection clustering, which is a technique to improve the scalability of iBGP, and other factors, such as intra-AS link costs, among others. In this paper, we provide a comprehensive solution that avoids all the known anomalies with both eBGP and iBGP. In our solution, each AS can locally choose its routing policies, while still ensuring anomaly-free behavior.

Internet is composed of a large amount of autonomous systems (ASes). Border Gateway Protocol (BGP) is the de facto standard used to connect these ASes and exchange reachability information between them. The global BGP routing table size in default free zone (DFZ) grows fast due to many factors including IP address allocation, multihoming, and traffic engineering, etc. Increasing prefix fragments consume more memory space and computational capacity in network forwarding devices. It has been known that the Internet has a potential routing scalability issue along with large address space (e.g., IPv6) deployment in the future. Route aggregation is a practical approach to reduce route entries. In this paper, we propose an innovation based on BGP, named Aggregation-aware Inter-Domain Routing (AIDR). It takes advantage of the redundant paths to the same destination in the Internet, and takes route aggregation into account in route selection to get more aggregation for forwarding table (FIB). We give a detailed analysis and evaluation on the effect of AIDR using the public BGP traces from RouteViews and RIPE. It shows that AIDR can produce aggregated FIBs of size roughly 20%~36% of the original routing table size with allowing 2.0 AS path stretch, and 25%~40% without AS path tretch.

The Minimal Route Advertisement Interval (MRAI) plays a prominent role in convergence of the Border Gateway Protocol (BGP). Previous studies have suggested using adaptive MRAI and reusable timers to reduce the BGP convergence time. The adaptive MRAI timers perform well under the normal load of BGP updates. However, a large number of BGP updates may flood Internet routers. We propose a new algorithm, MRAI with Flexible Load Dispersing (FLD-MRAI), which reduces the router's overhead by dispersing the load in case of a large number of BGP updates. We also examine the MRAI timers under the normal load of BGP updates. Since BGP routing policies play a significant role in preserving the Internet routing stability, we evaluate their impact on BGP convergence time and Route Flap Damping (RFD) algorithms. The proposed algorithms are evaluated using the ns-BGP network simulator.

The Internet consists of rapidly increasing number of hosts interconnected by constantly evolving networks of links and routers. Interdomain routing in the Internet is coordinated by the Border Gateway Protocol (BGP). The BGP allows each autonomous system (AS) to choose its own administrative policy in selecting routes and propagating reachability information to others. These routing policies are constrained by the contractual commercial agreements between administrative domains. For example, an AS sets its policy so that it does not provide transit services between its providers. Such policies imply that AS relationships are an important aspect of the Internet structure. We propose an augmented AS graph representation that classifies AS relationships into customer-provider, peering, and sibling relationships. We classify the types of routes that can appear in BGP routing tables based on the relationships between the ASs in the path and present heuristic algorithms that infer AS relationships from BGP routing tables. The algorithms are tested on publicly available BGP routing tables. We verify our inference results with AT&T internal information on its relationship with neighboring ASs. As much as 99.1% of our inference results are confirmed by the AT&T internal information. We also verify our inferred sibling relationships with the information acquired from the WHOIS lookup service. More than half of our inferred sibling-to-sibling relationships are confirmed by the WHOIS lookup service. To the best of our knowledge, there has been no publicly available information about AS relationships and this is the first attempt in understanding and inferring AS relationships in the Internet. We show evidence that some routing table entries stem from router misconfigurations.

The Border Gateway Protocol (BGP) is the de facto interdomain routing protocol used to exchange network reachability information between ASes in the global Internet. However, Varadhan et al. [19] has shown that the conflict of BGP routing policies can cause BGP to diverge. This paper presents an approach to seek the set of conflict routing policies based on dispute cycle avoidance. The stable paths problem, a static formalism that captures the semantics of interdomain routing protocol, provides the theoretical foundation for this approach. And this approach draws on the simple path vector protocol to identify the dispute cycles that cause routing oscillation first, and then queries which routing policies lead to these cycles in a distributed manner. Finally, it determines conflict routing policies based on dispute cycle avoidance. Moreover, we present a method to determine the severity level of dispute routing policies based on AS relationships and configuration guidelines of routing policy presented by Gao and Rexford [4]. And this method can help Network administrators determine the top-priority routing policies to be fixed and improve the efficiency of debugging routing policies. In addition, a simulation instance is given in order to explain results of this method.

BGP (Border Gateway Protocol) is one of the core internet backbone protocols, which were designed to address the large-scale routing among the ASes (Autonomous System) in order to ensure the reachability among them. However, an attacker can inject update messages into the BGP communication from the peering BGP routers and those routing information will be propagated across the global BGP routers. This could cause disruptions in the normal routing behavior. Specially crafted BGP messages can reroute the traffic path from a source ASN to a specific destination ASN via another path and this attack is termed as AS Path Hijacking. This research work is focused on the detection of suspicious deviation in the AS path between a source and destination ASNs, by analyzing the BGP update messages that are collected by passive peering to the BGP routers. The research mainly focuses on identifying the AS Path Hijacking by quantifying: (1). How far the deviation occurred for a given AS Path and (2). How much credible is the deviated AS path. We propose a novel approach to calculate the deviation occurred by employing weighted edit distance algorithm. A probability score using n-gram frequency is used to determine credibility of the path. Both the scores are correlated together to determine whether a given AS Path is suspicious or not. The experimental results show that our approach is capable of identifying AS path hijacks with low false positives.

Inter-domain routing protocol routes network reachability information between autonomous systems (ASs) in the network. Network reachability information contains the details about the neighbors of the ASs and it contains messages used to maintain the connection between ASs. On one hand, given the size and the rapid growth of the Internet, any inter-domain routing protocol should satisfy basic desirable algorithmic properties, such as scalability, robustness and rapid convergence by Griffin, T., and Wilford, G. 1999. On the other hand, for economic reasons inter-domain routing should support policy routing, where Internet service providers (ISPs) have the flexibility to implement a wide variety of private routing policies that ISPs choose not to reveal. Moreover, the routing protocol should provide sufficient information to enable ISPs to make informed policy decisions. Border gateway protocol (BGP) by Goodell, G. et al. (2003) is the inter-domain routing protocol that is currently being used. BGP has a number of problems which includes scalability and large convergence time by Labovitz, C et al. (2000). This paper explains in detail the alternative to BGP which is the hybrid optimized link-state path-vector routing protocol (HLP) [1] and gives a comparison based on the simulation of these protocols. The comparison shows us that HLP overcomes some of the important problems faced in BGP.

In spite of significant on-going research, the Border Gateway Protocol (BGP) still encompasses conceptual vulnerability issues regarding impersonating the ownership of IP prefixes for ASes (Autonomous Systems). In this context, a number of research studies focused on securing BGP through historical-based and statistical-based behavioural models. This paper improves the earlier IP prefix hijack detection method presented in (Alshamrani et al. 2015) by identifying false positives showing up due to the organisations that may use multiple ASNs (Autonomous System Numbers) to advertise their routes. To solve this issue, we link a Verification Database to the previously proposed detection method to improve the accuracy. The method extracts the organisation names (unique code) and associated ASNs from different ASN delegators and RIRs (Regional Internet Registries), more specifically the RIPE (Reseaux IP Europeans) dump database (John Stamatakis 2014) in order to evaluate the method. Since the organisation name is not available in the BGP updates, the data are extracted and processed to produce a structured database (Verification DB). The algorithm excludes false positive IP prefix hijack detection events in the SFL (Suspicious Findings List) introduced in (Alshamrani et al. 2015). Finally, the algorithm is validated using the 2008 YouTube Pakistan hijack event and the Con-Edison hijack (2006); the analysis demonstrates that the improved algorithm qualitatively increases the accuracy of detecting the IP prefix hijacks, specifically reducing the false positives.

The border gateway protocol (BGP) is the default inter domain routing protocol used on the internet for exchanging information between autonomous systems. Available literature suggests that BGP is vulnerable to session hijacking attacks. There are a number of proposals aimed at improving BGP security which have not been fully implemented. This paper examines a number of approaches for securing BGP through a comparative study and identifies the reasons why these proposals have not been implemented commercially. This paper analyses the architecture of internet routing and the design of BGP while focusing on the problem of BGP session hijacking attacks. Using Graphical Network Simulator 3 (GNS-3), a session hijack is demonstrated and a solution which involves the implementation of route filtering, policy-maps and route-maps on CISCO routers representing ASes is carried out. In the end, a workable industry standard framework for securing and protecting BGP sessions and border routers from exploitation with little or no modification to the existing routing infrastructure is demonstrated.

Border gateway protocol (BGP) version 4 is routing current Internet for more than 20 years. BGP is the only protocol that has proven its routing capability of such size network with continually growing nature. Although BGP is scalable and network layer reachability information it lacks quality of service metrics like latency. BGP routing decision algorithm uses as-path length between autonomous systems (AS) as main factor for most of its best-path calculations. Because of more affordable peering architectures as-path length is generally decreasing in worldwide internet network resulting in less efficient routes for real-time internet protocol traffic. This study proposes future internet architecture consisting of multiple AS which provide latency aware routing in software defined network (SDN). For highest reliability there are bilateral latency measurements between each pair of connected autonomous systems. Latency measurement results are stored in distributed decentralized blockchain network where each AS holds its share. Each AS hosts an SDN instance for interconnection with neighbor SDN controllers over AS border. SDN instances processes latency measurement data from blockchain network, validates data integrity and manages latency aware routing for real-time data flows.

Border Gateway Protocol (BGP) is a widely used Internet routing protocol. While several security features have been introduced and implemented to prevent attacks and address routing instabilities, BGP remains vulnerable due to lack of integrity and authentication of BGP messages. BGP operations strongly depend on its security and attacks on BGP adversely influence packet routing. Given the importance of BGP security, several approaches have been developed to enhance security of BGP sessions. The Resource Public Key Infrastructure (RPKI), a specialized Public Key Infrastructure (PKI), was developed to help secure the Internet routing. It uses cryptographically verifiable statements to ensure that Autonomous Systems (ASes), the Internet resource holders, are certifiably linked to the routing information they generate thus resulting in a reliable routing origin. In this paper, we describe a testbed developed for validating route origin and present simulation results.

The Border Gateway Protocol (BGP) is a routing protocol used to exchange routing information between autonomous systems. The decentralized nature of inter-networks makes them more vulnerable to BGP hijacking attacks, which maliciously modify BGP routes, potentially intercepting sensitive data and causing disruptions to services. In this paper, we proposed a novel path-based routing anomaly detection algorithm that combines both attributes and topological information from BGP routing tables to accurately identify anomalies and protect against BGP hijacking. The algorithm introduces a random walk path sampling and modeling method that effectively captures the underlying structure of the routing table.