ISP Column - May 2026

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Centrality in the DNS

May 2026

Geoff Huston

This is a topic I looked at in November 2022, and I would like to return to it here, so see if anything has changed in the landscape of the DNS. Is centrality in the DNS largely unchanged, or have aspects of this activity become even more centralised today as compared to four years ago?

The Internet's Domain Name System undertakes a vitally important role in today's Internet. Originally conceived as a human-friendly way of specifying the location of the other end of an Internet transaction, it became the name of a service point during the Internet's transition to a client/server architecture. A domain name was still associated with an IP address, but that 1:1 unique association was weakened when we started adjustments to respond to IPv4 address exhaustion. The address space is now highly fragmented and chaotic while it’s the name space that provides the essential common referential framework that defines the Internet itself. Indeed, it has been argued that today the Internet runs on names, where IP addresses serve an ephemeral role as routing locators to aid packet transmission. These days, it's names that serve as stable endpoint identifiers, act as the mainstay of assuring clients as to the authenticity of service transactions and are the foundation of a single common referential framework that defines the Internet. When we consider centrality in the infrastructure Internet, the topic of centrality in the roles that support the name infrastructure, the DNS, is the most vital topic in this space.

The Internet was a product of progressive deregulation of public telephony, pulling apart the former framework of regulated national monopolies operating largely as public sector entities, constrained terms of trade and tightly constrained technology evolution, and replacing it with a framework of diverse private sector operations, using the rigor of competition to ensure that the market of for telecommunications services was efficient and focussed on the needs of users. It is uncommon for markets to naturally operate in such a manner and there are many forms of distortion to allow some market actors to gain undue advantage over their competitors. Identifying and correcting such market distortions is typically the role of a public sector market regulator, who is typically given powers to remedy such situations. This is important in any market-based activity sector, but is particularly important, and challenging, when we consider the Internet as a global market. While the demand for public sector oversight and potential intervention is no less important, the issues of defining appropriate governance measures in this international space can pose unique issues and at times unique solutions. For example, the European Union has established a robust framework for regulatory penalties that can be calculated based on a company's total worldwide turnover rather than just EU-specific earnings. These penalties are designed to provide adequate motivation for compliance with EU regulations across sectors, particularly for large multinational enterprises.

As a collection of inter-twined markets, aspects of the Internet has been prone to excessive market distortions that can be characterized as an extreme case of early-comer advantage where one, or a small clique, of early entrants into a market sector become completely dominant to the extent that there is no effective competition and no possibility of admitting additional market entrants. This form of market dominance is often termed "centrality". A good example is Internet search, where Google's search engine quickly assumed a position of global dominance which it was able to maintain for some decades. (Google currently has some 90% of the search market across the global Internet, and the next largest search provider, Microsoft's Bing, has some 5% market share, according to data published by statscounter.) We are seeing the same tussle in the AI space at present, where a number of the global digital behemoths are rapidly investing in this space in an effort to establish longer term dominance and shut out all future competition.

However, to focus this narrative, the question here is: Is the DNS centralised?

A reason why this is a vitally important question might lie in aspects of original development of the DNS.

The early days of the DNS started with a name system that had a small collection of top-level domains, namely .com, .net, .org, .gov, .edu and .mil. The first wave of expansion of this name system was through the adoption of the two-letter country codes as top-level domains. The IANA (which at the time was synonymous with Jon Postel, in his role as the Internet's record keeper of names and addresses) would delegate the DNS equivalent of the ISO two-letter country code to an entity from the country in question to administer this...