Characterization of Anycast Adoption in the DNS Authoritative Infrastructure

Anycast has proven to be an effective mechanism to enhance resilience in the DNS ecosystem and for scaling DNS nameserver capacity, both in authoritative and the recursive resolver infrastructure. Since its adoption for root servers, anycast has mitigated the impact of failures and DDoS attacks on the DNS ecosystem. In this work, we quantify the adoption of anycast to support authoritative domain name service for top- level and second-level domains (TLDs and SLDs). Comparing two comprehensive anycast census datasets in 2017 and 2021, with DNS measurements captured over the same period, reveals that anycast adoption is increasing, driven by a few large operators. While anycast offers compelling resilience advantage, it also shifts some resilience risk to other aspects of the infrastructure. We discuss these aspects, and how the pervasive use of anycast merits a re-evaluation of how to measure DNS resilience

Workshop on Overcoming Measurement Barriers to Internet Research (WOMBIR 2021) Final Report

In January and April 2021 we held the Workshop on Overcoming Measurement Barriers to Internet Research (WOMBIR) with the goal of understanding challenges in network and security data set collection and sharing. Most workshop attendees provided white papers describing their perspectives, and many participated in short-talks and discussion in two virtual workshops over five days. That discussion produced consensus around several points. First, many aspects of the Internet are characterized by decreasing visibility of important network properties, which is in tension with the Internet's role as critical infrastructure. We discussed three specific research areas that illustrate this tension: security, Internet access; and mobile networking. We discussed visibility challenges at all layers of the networking stack, and the challenge of gathering data and validating inferences. Important data sets require longitudinal (long-term, ongoing) data collection and sharing, support for which is more challenging for Internet research than other fields. We discussed why a combination of technical and policy methods are necessary to safeguard privacy when using or sharing measurement data. Workshop participant proposed several opportunities to accelerate progress, some of which require coordination across government, industry, and academia

Retroactive identification of targeted DNS infrastructure hijacking

In 2019, the US Department of Homeland Security issued an emergency warning about DNS infrastructure tampering. This alert, in response to a series of attacks against foreign government websites, highlighted how a sophisticated attacker could leverage access to key DNS infrastructure to then hijack traffic and harvest valid login credentials for target organizations. However, even armed with this knowledge, identifying the existence of such incidents has been almost entirely via post hoc forensic reports (i.e., after a breach was found via some other method). Indeed, such attacks are particularly challenging to detect because they can be very short lived, bypass the protections of TLS and DNSSEC, and are imperceptible to users. Identifying them retroactively is even more complicated by the lack of fine-grained Internet-scale forensic data. This paper is a first attempt to make progress at this latter goal. Combining a range of longitudinal data from Internet-wide scans, passive DNS records, and Certificate Transparency logs, we have constructed a methodology for identifying potential victims of sophisticated DNS infrastructure hijacking and have used it to identify a range of victims (primarily government agencies), both those named in prior reporting, and others previously unknown

Investigating the impact of DDoS attacks on DNS infrastructure

Denial of Service (DDoS) attacks both abuse and target core Internet infrastructures and services, including the Domain Name System (DNS). To characterize recent DDoS attacks against authoritative DNS infrastructure, we join two existing data sets – DoS activity inferred from a sizable darknet, and contemporaneous DNS measurement data – for a 17-month period (Nov. 20 - Mar. 22). Our measurements reveal evidence that millions of domains (up to 5% of the DNS namespace) experienced a DoS attack during our observation window. Most attacks did not substantially harm DNS performance, but in some cases we saw 100-fold increases in DNS resolution time, or complete unreachability. Our measurements captured a devastating attack against a large provider in the Netherlands (TransIP), and attacks against Russian infrastructure. Our data corroborates the value of known best practices to improve DNS resilience to attacks, including the use of anycast and topological redundancy in nameserver infrastructure. We discuss the strengths and weaknesses of our data sets for DDoS tracking and impact on the DNS, and promising next steps to improve our understanding of the evolving DDoS ecosystem

Where .ru?: assessing the impact of conflict on russian domain infrastructure

The hostilities in Ukraine have driven unprecedented forces, both from third-party countries and in Russia, to create economic barriers. In the Internet, these manifest both as internal pressures on Russian sites to (re-)patriate the infrastructure they depend on (e.g., naming and hosting) and external pressures arising from Western providers disassociating from some or all Russian customers. While quite a bit has been written about this both from a policy perspective and anecdotally, our paper places the question on an empirical footing and directly measures longitudinal changes in the makeup of naming, hosting and certificate issuance for domains in the Russian Federation