Border Gateway Protocol Routing Tables Research Articles

Designing a Border Gateway Protocol Player and Reviewing Machine Learning Technology

Border gateway protocol is the core routing protocol of the Internet and the glue that binds the countless of networks that comprise the Internet. In this paper, a border gateway protocol player that takes as input border gateway protocol routing tables and updates from major ISP routers will be designed. It can be used for routers to exchange a border gateway protocol messages with neighbor routers continually. Furthermore, it can pretend exact the same environment of routing tables for back in the designated period of time while routing tables were exchanged. Hence it helps a lot to research routing behaviors. We also review some of the machine learning related literatures. After read the paper, readers should be able to understand the purpose of the border gateway protocol and its behavior.

Shedding light on the use of AS relationships for path inference

Autonomous system (AS) business relationships and their inference have been widely studied by network researchers in the past. An important application of inferred AS relationships can be the prediction of AS paths between a source and destination AS within a model. However, besides knowing the topology and inferred AS relationships, AS path prediction within a model needs to be understood in order for us to know how we can derive border gateway protocol (BGP) policies from AS relationships. In this paper, we shed light onto the predictive capabilities of AS relationships by investigating whether they can be translated into BGP policies such that inferred AS paths are consistent with real AS paths, e.g., paths observed from BGP routing tables. Our findings indicate that enforcing constraints such as the well-known valley-free property and the widely assumed preference of customer routes always results in a very low consistency for AS path inference. In addition, this is true irrespective of whether customer, peer, or provider routes are preferred. Apparently, applying such constraints eliminates many “correct” paths that are observed in BGP routing tables and that are propagated in a simple shortest path model where AS relationships are ignored. According to our findings, deriving BGP routing policies for predicting with high accuracy AS paths in a model directly from AS relationships is still difficult.

Simple path diversity algorithm for interdomain routing

The border gateway protocol (BGP) handles the task of establishing paths between autonomous systems (AS). As the BGP does not incorporate measures of round-trip time into the decision and does not provide path diversity for a destination, this study proposes a simple path diversity algorithm (SPDA) for interdomain routing. The SPDA comprises three steps. First, the BGP is extended to allow the BGP routing table to save multiple paths for any destination. Second, a given source node determines whether the point of congestion occurs along the best path. Third, if congestion occurs along the best path, the source node specifies an alternate path and directs traffic over the best and alternate paths concurrently. Simulation results indicate that the SPDA produces better performance than existing approaches in average end-to-end delay, average packet loss rate and average throughput.

Persistent detection and recovery of state inconsistencies

Soft-state is a well established approach to designing robust network protocols and applications. However it is unclear how to apply soft-state approach to protocols that must maintain a large amount of state information in a scalable way. For example the Border Gateway Protocol (BGP) is used to maintain the global routing tables at core Internet routers, and the table size is typically above 180,000 entries and continues to grow over time. In this paper, we propose a novel approach, Persistent Detection and Recovery (PDR), to enable large-state protocols and applications to maintain state consistency using a soft-state approach. PDR uses state compression and receiver participation mechanisms to avoid per-state refresh overhead. We evaluate PDR's effectiveness and scalability by applying its mechanisms to maintain the consistency of BGP routing tables between routers. Our results show that the proposed PDR mechanisms are effective and efficient in detecting and correcting route insertion, modification, and removal errors. Moreover, they eliminate the need for routers to exchange full routing tables after a session reset, thus enabling routers to recover quickly from transient session failures.

Advanced Routing Worm and Its Security Challenges

Most well-known worms, such as Code Red, Slammer, Blaster, and Sasser, infected vulnerable computers by scanning the entire IPv4 address space. In this article, the authors present an advanced worm called the “routing worm,” which implements two new attacking techniques. First, a routing worm uses Border Gateway Protocol (BGP) routing tables to only scan the Internet-routable address space, which allows it to propagate three times faster than a traditional worm. Second, and more important, the geographic information of BGP routing prefixes enables a routing worm to conduct pinpoint “selective attacks” by imposing heavy damage to vulnerable computers in a specific country, company, Internet Service Provider, or autonomous system, without collateral damage done to others. Because of the inherent publicity of BGP routing tables, attackers can easily deploy routing worms, which distinguishes the routing worm from other“worst-case” worms. Compared to a traditional worm, a routing worm could possibly cause more severe congestion to the Internet backbone since all scans sent out by it are Internet routable (and can be dropped only at the destination local networks). In addition, it is harder to quickly detect a routing worm-infected computer since we cannot distinguish illegal scans from regular connections sent out from it without waiting for traffic responses. For high-fidelity Internet-scale worm simulations, through this routing worm study, the authors emphasize the importance of simulating failed worm scans and distinguishing nonroutable worm scans from routable scans. In order to defend against routing worms and all scanning worms, an effective way is to upgrade the current Internet from IPv4 to IPv6, although such an upgrade will require a tremendous effort and is still a controversial issue.

The impact of BGP dynamics on intra-domain traffic

Recent work in network traffic matrix estimation has focused on generating router-to-router or PoP-to-PoP (Point-of-Presence) traffic matrices within an ISP backbone from network link load data. However, these estimation techniques have not considered the impact of inter-domain routing changes in BGP (Border Gateway Protocol). BGP routing changes have the potential to introduce significant errors in estimated traffic matrices by causing traffic shifts between egress routers or PoPs within a single backbone network. We present a methodology to correlate BGP routing table changes with packet traces in order to analyze how BGP dynamics affect traffic fan-out within a large "tier-1" network. Despite an average of 133 BGP routing updates per minute, we find that BGP routing changes do not cause more than 0.03% of ingress traffic to shift between egress PoPs. This limited impact is mostly due to the relative stability of network prefixes that receive the majority of traffic -- 0.05% of BGP routing table changes affect intra-domain routes for prefixes that carry 80% of the traffic. Thus our work validates an important assumption underlying existing techniques for traffic matrix estimation in large IP networks.

Study of Internet autonomous system interconnectivity from BGP routing tables

Recently, several authors have proposed models based on power-laws to characterize Internet topologies . Most of these works use the BGP (Border Gateway Protocol) tables published by Oregon Route Views. The adjacency matrix containing AS (autonomous system) connectivity is built from a BGP table. Having access to BGP routing tables from several geographical sites gives a broader vision of ASs connectivity, since several ASs and links may be hidden for an AS due to routing processes policies, while they may be visible to other ASs. We compare BGP tables of different sizes and enrich the adjacency matrix with the union of them. This comparison is based on the AS degree connectivity , clustering coefficient and path length. Our initial results, published in [Proceedings of HPSR2003, Torino, Italy, June 2003], show an increment of 16% in the number of links and 0.7% in the number of ASs and show that a medium-size AS can get a vision similar to a repository such as Route Views. Most of the recent works analyze whether power-law distributions, also called scale-free models, arise on Internet topologies for the whole AS-level graph. However, few ones study whether the AS connectivity of the Internet core follows a power-law distribution. Here we use well-known heuristics to identify AS peeringship and split the Internet core from small regional ISPs and end customers. We will see that the Internet core does not fit a power-law well.

Study of Internet autonomous system interconnectivity from BGP routing tables

Recently, several authors have proposed models based on power-laws to characterize Internet topologies. Most of these works use the BGP (Border Gateway Protocol) tables published by Oregon Route Views. The adjacency matrix containing AS (autonomous system) connectivity is built from a BGP table. Having access to BGP routing tables from several geographical sites gives a broader vision of ASs connectivity, since several ASs and links may be hidden for an AS due to routing processes policies, while they may be visible to other ASs. We compare BGP tables of different sizes and enrich the adjacency matrix with the union of them. This comparison is based on the AS degree connectivity, clustering coefficient and path length. Our initial results, published in [Proceedings of HPSR2003, Torino, Italy, June 2003], show an increment of 16% in the number of links and 0.7% in the number of ASs and show that a medium-size AS can get a vision similar to a repository such as Route Views. Most of the recent works analyze whether power-law distributions, also called scale-free models, arise on Internet topologies for the whole AS-level graph. However, few ones study whether the AS connectivity of the Internet core follows a power-law distribution. Here we use well-known heuristics to identify AS peeringship and split the Internet core from small regional ISPs and end customers. We will see that the Internet core does not fit a power-law well.

On inferring autonomous system relationships in the Internet

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.