BGP route prediction within ISPs

IEEE/ACM Trans. Networking

Battista

2015

Internet service providers (ISPs) run the internal Border Gateway Protocol (iBGP) to distribute interdomain routing information among their BGP routers. Previous research consistently assumed that iBGP is always configured as a mere dispatcher of interdomain routes. However, router configuration languages offer operators the flexibility of fine-tuning iBGP. In this paper, we study the impact of deploying routing policies in iBGP. First, we devise a provably correct inference technique to pinpoint iBGP policies from public BGP data. We show that the majority of large transit providers and many small transit providers do apply policies in iBGP. Then, we discuss how iBGP policies can help achieve traffic engineering and routing objectives. We prove that, unfortunately, the presence of iBGP policies exacerbates the iBGP convergence problem and invalidates fundamental assumptions for previous results, affecting their applicability. Hence, we propose provably correct configuration guidelines to achieve traffic engineering goals with iBGP policies, without sacrificing BGP convergence guarantees. Finally, for the cases in which our guidelines are not applicable, we propose a novel technique to verify the correctness of an iBGP configuration with iBGP policies. We implement a prototype tool and show the feasibility of offline analyses of arbitrary policies on both real-world and in vitro configurations.

Section: Checker For Ibgp Policy Configurationsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

On iBGP Routing Policies

Vissicchio

IEEE/ACM Trans. Networking

Battista

2015

“…Most of the existing literature (e.g., [2], [7], [9]) assumes that iBGP acts as a simple dispatcher of inter-domain routes, with routing policies applied exclusively to eBGP sessions. However, a significant amount of ISPs do apply iBGP policies [3], in the sense that they intentionally modify attributes on iBGP messages, e.g., to increase internal routing flexibility and improve traffic engineering.…”

Section: Ibgp Policiesmentioning

confidence: 99%

“…While eBGP routing policies are deeply studied (e.g., [2], [4], [5]), few things are known about iBGP policies. Nevertheless, estimating the popularity of iBGP policies has important implications [6] on the applicability of previously proposed theoretical insights (e.g., [7]), protocol enhancements (e.g., [8]), and tools (e.g., [9]), which assume that policies are applied solely in eBGP.…”

Section: Introductionmentioning

confidence: 99%

On the quality of BGP route collectors for iBGP policy inference

2014 IFIP Networking Conference

Vissicchio

Donnet

2014

Abstract-A significant portion of what is known about Internet routing stems out from public BGP datasets. For this reason, numerous research efforts were devoted to (i) assessing the (in)completeness of the datasets, (ii) identifying biases in the dataset, and (iii) augmenting data quality by optimally placing new collectors. However, those studies focused on techniques to extract information about the AS-level Internet topology.In this paper, we show that considering different metrics influences the conclusions about biases and collector placement. Namely, we compare AS-level topology discovery with iBGP policy inference. We find that the same datasets exhibit significantly diverse biases for these two metrics. For example, the sensitivity to the number and position of collectors is noticeably different. Moreover, for both metrics, the marginal utility of adding a new collector is strongly localized with respect to the proximity of the collector. Our results suggest that the "optimal" position for new collectors can only be defined with respect to a specific metric, hence posing a fundamental trade-off for maximizing the utility of extensions to the BGP data collection infrastructure.

“…Results of such an effort encompass formal analyses of the protocol (e.g., [2], [3]), experimental measurements of disruptions due to BGP (e.g., [4], [5]), proposal of configuration guidelines (e.g., [6]) and of protocol modifications (e.g., [7]), and practical approaches to check a given configuration for correctness (e.g., [8], [9]). However, all previous studies missed a fundamental analogy: Basic BGP configurations can encode elementary logic gates but also, memory and clock components.…”

Section: Introduction and Related Workmentioning

confidence: 99%

Using routers to build logic circuits: How powerful is BGP?

Chiesa

2013 21st IEEE International Conference on Network Protocols (ICNP)

Battista

et al. 2013

Abstract-Because of its practical relevance, the Border Gateway Protocol (BGP) has been the target of a huge research effort since more than a decade. In particular, many contributions aimed at characterizing the computational complexity of BGPrelated problems. In this paper, we answer computational complexity questions by unveiling a fundamental mapping between BGP configurations and logic circuits. Namely, we describe simple networks containing routers with elementary BGP configurations that simulate logic gates, clocks, and flip-flops, and we show how to interconnect them to simulate arbitrary logic circuits. We then investigate the implications of such a mapping on the feasibility of solving BGP fundamental problems, and prove that, under realistic assumptions, BGP has the same computing power as a Turing Machine. We also investigate the impact of restrictions on the expressiveness of BGP policies and route propagation (e.g., route propagation rules in iBGP and Local Transit Policies in eBGP) and the impact of different message timing models. Finally, we show that the mapping is not limited to BGP and can be applied to generic routing protocols that use several metrics.