Interdomain Route Leak Mitigation: A Pragmatic Approach

The Internet has grown to support many vital functions, but it is not administered by any central authority. Rather, the many smaller networks that make up the Internet - called Autonomous Systems (ASes) - independently manage their own distinct host address space and routing policy. Routers at the borders between ASes exchange information about how to reach remote IP prefixes with neighboring networks over the control plane with the Border Gateway Protocol (BGP). This inter-AS communication connects hosts across AS boundaries to build the illusion of one large, unified global network - the Internet. Unfortunately, BGP is a dated protocol that allows ASes to inject virtually any routing information into the control plane. The Internet’s decentralized administrative structure means that ASes lack visibility of the relationships and policies of other networks, and have little means of vetting the information they receive. Routes are global, connecting hosts around the world, but AS operators can only see routes exchanged between their own network and directly connected neighbor networks. This mismatch between global route scope and local network operator visibility gives rise to adverse routing events like route leaks, which occur when an AS advertises a route that should have been kept within its own network by mistake. In this work, we explore our thesis: that malicious and unintentional route leaks threaten Internet availability, but pragmatic solutions can mitigate their impact. Leaks effectively reroute traffic meant for the leak destination along the leak path. This diversion of flows onto unexpected paths can cause broad disruption for hosts attempting to reach the leak destination, as well as obstruct the normal traffic on the leak path. These events are usually due to misconfiguration and not malicious activity, but we show in our initial work that vrouting-capable adversaries can weaponize route leaks and fraudulent path advertisements to enhance data plane attacks on Internet infrastructure and services. Existing solutions like Internet Routing Registry (IRR) filtering have not succeeded in solving the route leak problem, as globally disruptive route leaks still periodically interrupt the normal functioning of the Internet. We examine one relatively new solution - Peerlocking or defensive AS PATH filtering - where ASes exchange toplogical information to secure their networks. Our measurements reveal that Peerlock is already deployed in defense of the largest ASes, but has found little purchase elsewhere. We conclude by introducing a novel leak defense system, Corelock, designed to provide Peerlock-like protection without the scalability concerns that have limited Peerlock’s scope. Corelock builds meaningful route leak filters from globally distributed route collectors and can be deployed without cooperation from other network

Dovetail: Stronger Anonymity in Next-Generation Internet Routing

Current low-latency anonymity systems use complex overlay networks to conceal a user's IP address, introducing significant latency and network efficiency penalties compared to normal Internet usage. Rather than obfuscating network identity through higher level protocols, we propose a more direct solution: a routing protocol that allows communication without exposing network identity, providing a strong foundation for Internet privacy, while allowing identity to be defined in those higher level protocols where it adds value. Given current research initiatives advocating "clean slate" Internet designs, an opportunity exists to design an internetwork layer routing protocol that decouples identity from network location and thereby simplifies the anonymity problem. Recently, Hsiao et al. proposed such a protocol (LAP), but it does not protect the user against a local eavesdropper or an untrusted ISP, which will not be acceptable for many users. Thus, we propose Dovetail, a next-generation Internet routing protocol that provides anonymity against an active attacker located at any single point within the network, including the user's ISP. A major design challenge is to provide this protection without including an application-layer proxy in data transmission. We address this challenge in path construction by using a matchmaker node (an end host) to overlap two path segments at a dovetail node (a router). The dovetail then trims away part of the path so that data transmission bypasses the matchmaker. Additional design features include the choice of many different paths through the network and the joining of path segments without requiring a trusted third party. We develop a systematic mechanism to measure the topological anonymity of our designs, and we demonstrate the privacy and efficiency of our proposal by simulation, using a model of the complete Internet at the AS-level

Antitrust Analysis for the Internet Upstream Market: A BGP Approach

In this paper we study concentration in the European Internet upstream access market. The possibility of measuring market concentration depends on a correct definition of the market itself; however, this is not always possible, since, as it is the case of the Internet industry, very often Antitrust authorities lack reliable pricing and traffic data. This difficulty motivates our paper. We present an alternative approach based on the inference of the Internet Operators interconnection policies using micro-data sourced from their Border Gateway Protocol tables. We assess market concentration following a two step process: firstly we propose a price-independent algorithm for defining both the vertical and geographical relevant market boundaries, then we calculate market concentration indexes using two novel metrics. These assess, for each undertaking, both itsrole in terms of essential network facility and of wholesale market dominance. The results, applied to four leading Internet Exchange Points in London, Amsterdam, Frankfurt and Milan, show that some vertical segments of these markets are highly concentrated, while others are extremely competitive. According to the Merger Guidelines some of the estimated market concentration values would immediately fall within the special attention category.Technology and Industry, Other Topics

Antitrust Analysis for the Internet Upstream Market: a BGP Approach

In this paper we study concentration in the European Internet upstream access market. Measurement of market concentration depends on correctly defining the market, but this is not always possible as Antitrust authorities often lack reliable pricing and traffic data. We present an alternative approach based on the inference of the Internet Operators interconnection policies using micro-data sourced from their Border Gateway Protocol tables. Firstly we propose a price-independent algorithm for defining both the vertical and geographical relevant market boundaries, then we calculate market concentration indexes using two novel metrics. These assess, for each undertaking, both its role in terms of essential network facility and of wholesale market dominance. The results, applied to four leading Internet Exchange Points in London, Amsterdam, Frankfurt and Milan, show that some vertical segments of these markets are extremely competitive, while others are highly concentrated, putting them within the special attention category of the Merger Guidelines

Practicable route leak detection and protection with ASIRIA

Route leak events have historically caused many wide-scale disruptions on the Internet. Leaks are particularly hard to detect because they most frequently involve routes with legitimate origin announced through legitimate paths that are propagated beyond their legitimate scope. In this paper we present ASIRIA, a mechanism for detecting and avoiding leaked routes and protecting against leakage events that uses AS relationship information inferred from the Internet Routing Registries. By relying on existing information, ASIRIA provides immediate benefits to early adopters. In particular, we consider the deployment of ASIRIA to detect leaks caused by over 300 ASes and we show that it can detect over 99% of the leakage events generated by a customer or a peer solely using currently available information in 90% of the cases.This work has been partially supported by Huawei through the Internet Routing Blockchain project, by the EU through the NGI Atlantic MCCA project and the Madrid Government (Comunidad de Madrid Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M21), and in the context of the V PRICIT (Regional Programme of Research and Technological Innovation