Evidence of Decreasing Internet Entropy: The Lack of Redundancy in DNS Resolution by Major Websites and Services

Abstract

This paper analyzes the extent to which the Internet’s global domain name resolution (DNS) system has preserved its distributed resilience given the rise of cloud-based hosting and infrastructure. We explore trends in the concentration of the DNS space since at least 2011. In addition, we examine changes in domains’ tendency to “diversify” their pool of nameservers – how frequently domains employ DNS management services from multiple providers rather than just one provider – a comparatively costless and therefore puzzlingly rare decision that could supply redundancy and resilience in the event of an attack or service outage affecting one provider.