DNS root server. How many DNS root servers does the Internet need today?

DNS server DNS

You want to know what a DNS server is? We explain it to you!

Anyone who has a lot to do with the Internet will certainly stumble across some cryptic terms. These include URL, PPPoE and the DNS server. In the following, you will learn what this is all about.

DNS server – what is that actually?

DNS stands for “Domain Name System”. Computers and other network devices on the Internet use an IP address. If you now want to call up a website on the Internet, the IP address is queried. The process is similar to dialing a phone number to connect to a person you want to reach. With DNS, you don’t have to remember every numeric combination of IP addresses. Instead, you simply connect to the DNS server, which maintains a huge database and maps website names to IP addresses. So the DNS works much like a phone book. You know the caller’s name, but not their phone number. The user knows the domain – for example, https://www.heise.de/tipps-tricks. This is sent as a request to the Internet, where the DNS then converts the domain into the corresponding IP address. For heise.de/tipps-tricks, for example, there is the IPv4 address or the IPv6 address 2a02:2e0:3fe:1001:7777:772e:2:85. Thanks to DNS, you don’t have to remember these complicated sequences of digits.

By the way, there is not just one DNS server. There are a total of thirteen root servers worldwide. So it can happen that a DNS server cannot assign an IP address to the requested URL. In this case, the request is simply passed on to the next server. If none of the servers can answer the entry, you will receive an error message in the browser. As a rule, the problem then lies with the address entered. Perhaps a typing error or transposed number is to blame.

The operators of the central root servers of the Domain Name System (DNS) want to subject themselves to self-regulation under the umbrella of the Internet Corporation for Assigned Names and Numbers (ICANN). In the future, it will be possible to change the operators of the 13 servers and to change the number of servers. This is tantamount to a small revolution in the DNS. The 13 root servers, which are at the top of the DNS hierarchy, always have the latest information about which address zones can be found where in the network.

Ever since the U.S. government handed over control of the central root zone to ICANN and its “community” or “stakeholders,” the question of who actually governs the central root servers has become increasingly urgent.

A total of twelve private companies, universities or organizations operate the 13 root servers for the DNS. Only three are located outside the USA. Three are operated by US authorities – NASA, the US Department of Defense and the US Army Research Lab. It is true that some of the operators now also offer the root zone decentrally at around 1,000 locations around the world using anycast technology. But covetousness, for example from China, to operate their own root servers, repeatedly caused debates as to why there could not be 14 or 15 servers.

Secretariat, governance and money

At the ICANN meeting, the root operators now presented their concept for the future. Based on measurements of bandwidth, number of requests per second and packets per second (bandwidth, packets/s, queries/s), the future root server system’s Strategy, Architecture and Policy (SAPF) division is to make recommendations on what total capacity and technical resources will be needed. “It may be less than 12 operators. And that’s probably where we’ll end up,” said Tripti Sinha, CTO of the University of Maryland’s Information Technology Division. Sinha is vice chair of ICANN’s Root Server Advisory Committee and operator of the D-Root server.

SAPF is not the only new department for future root server oversight. Additional full-time staff will provide measurement and monitoring data – continuously checking that root operators are meeting appropriate service level agreements. In addition, Sinha and her colleagues recommend institutionalizing the previously loose secretariat of the Twelve, an extra finance department, and a small team to handle the selection of new root operators.

Quality control and new applicants

If a root operator leaves, voluntarily or because of deficiencies in quality or does not adhere to the agreed principles of non-discrimination, SAPF recommends a new operator to ICANN, according to the concept – and in the future there will also be, what has been remarkably missing so far, regular contracts for this.

For decades, companies and public organizations have provided the basic Internet service voluntarily, on a free-floating basis, and at their own expense. As the network grows, something has to change there, too, write the Twelve. In the future, the beneficiaries of the root server system, first and foremost ICANN, will have to pay for operation, research and possible emergencies. How much is yet to be calculated.

Decentralization or centralization elsewhere

The small revolution, on which ICANN’s board of directors, but also the self-governing bodies, are to decide next, is a reaction to the enormous growth of the network. However, the willingness to make changes is perhaps also due to the fact that alternatives to centralized organization have long been under discussion or are on their way. For example, there are efforts to push the “localroot” project, in which each DNS resolver operator maintains the root zone directly. On the other hand, large centralized resolvers, from Google’s to Quad9 to Cloudflares, are increasingly stealing the show from centralized root servers.