SIDN Labs study: internet centralisation evident in the Netherlands and elsewhere
Half of name servers not distributed across networks
Internet measurements by SIDN Labs show that centralisation is a potential problem within the .nl domain. Reliance on a small number of public recursive resolvers – systems that look up domain names – is growing, for example. And 48 per cent of all active .nl domains are now hosted by just three big companies. What's more, nearly half of .nl domain names don't have their name servers – systems that provide information in answer to domain name look-ups – distributed across different networks. That makes those domain names vulnerable to network problems.
Major recent outages affecting providers such as Akamai and OVHcloud haven't led to better distribution. On the contrary: the number of domain names whose name servers aren't distributed across multiple networks has actually gone up in the last year. SIDN Labs' researchers warn that increased dependence on a small number of service providers represents a security and stability risk. With so many name servers managed by so few providers, an outage affecting one big player could leave a large number of .nl domain names non-functional.
Figure 1: Distribution of .nl name servers across distinct networks.
Insight into developments
Growing domain name centralisation is one of the findings highlighted in a report by SIDN Labs. The state of .nl describes developments in and around the .nl domain on the basis of measurements of the Domain Name System (DNS). The DNS is the worldwide mechanism that translates domain names into IP addresses.
Figure 2: The most popular words in .nl registrations in 2021.
Among the things picked up by the measurements is how the coronavirus pandemic affected registrations. The words 'test' and 'PCR' were used in domain names far more often in 2021 than the year before, for example. Technological developments left their mark as well, with words such as 'meta', 'crypto' and 'verse' becoming popular with domain name registrants.
House-for-sale sites
Another striking trend detected by the researchers was the increasing use of 'straat' ('street') and 'laan' ('lane') in domain names – nearly always as part of a property address. It's now common for people selling houses, especially higher-value houses, to make information about the property available on a specially created website with a domain name based on the address.
Figure 3: Word cloud of the most popular terms in newly registered .nl domain names in August 2021.
SIDN Labs also investigated the web page context of the words used in .nl domain names. Again, the influence of the pandemic was prominent. For example, in 2018 the word 'corona' was used mainly in connection with words such as 'desperados' and 'cerveza'. Whereas last year it was typically associated with 'covid', 'lockdown' and other such words. Similarly, 'crisis' was used largely in the context of the pandemic in 2021, having had predominantly economic connotations in 2018.
Online society
SIDN Labs' Director Cristian Hesselman explained the background to the report: "Our aim was to present the results of our DNS measurements in an accessible form. So, as well as discussing the numbers themselves, we've put our findings in their broader social context. Because the online world is very much a reflection of what's happening in society." Hesselman is concerned about an increasingly large proportion of internet services being delivered by an increasingly small number of providers – not all of them US 'big tech' corporations. "The centralisation of name servers and resolvers increases the risk associated with an outage. And the majority of .nl domain names now rely on a single mail server IP address. So, if the associated network goes down, the domain name's mail service goes down as well."
Fifth biggest in the world
According to the reported data, use of .nl was higher than ever in 2021. On 1 January 2022, the Dutch country-code TLD had 6,229,639 domain names. That's more than 100,000 up, from 6,109,589 a year earlier. Within Europe, only Germany and the United Kingdom have higher absolute numbers of domain names. Globally, .nl is the fifth biggest of all the country-code domains. Download the full report The state of .nl.
