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Frequently asked questions

  • I am looking for a domain name registrant. Where can I look it up?

    The Whois is an easy-to-use tool for checking the availability of a .nl domain name. If the domain name is already taken, you can see who has registered it.

    On the page looking up a domain name you will find more information about what a domain name is, how the Whois works and how the privacy of personal data is protected. Alternatively, you can go straight to look for a domain name via the Whois.

  • I would like to transfer my domain name to another registrar. What is the procedure?

    To get your domain name transferred, you need the token (unique ID number) for your domain name. Your existing registrar has the token and is obliged to give it to you within five days, if you ask for it. The procedure for changing your registrar is described on the page transferring your domain name.

  • The details registered about me/my company are incorrect or out of date. How can I get them updated?

    To update the contact details associated with your domain name, you need to contact your registrar. Read more about updating contact details.

  • Why is my domain name in quarantine?

    When a domain name is cancelled, we aren't told the reason, so we can't tell you. You'll need to ask your registrar. The advantage of quarantine is that, if a name's cancelled by mistake, you can always get it back.

    One common reason is that the contract between you and your registrar says you've got to renew the registration every year. If you haven't set up automatic renewal and you don't renew manually, the registration will expire.

  • Ik heb een klacht over mijn provider/registrar. Kan ik daarvoor bij SIDN terecht?

    Wanneer je een klacht hebt over of een geschil met je registrar dan zijn er verschillende mogelijkheden om tot een oplossing te komen. Hierover lees je meer op pagina klacht over registrar. SIDN heeft geen formele klachtenprocedure voor het behandelen van een klacht over jouw registrar.

  • What conditions do I have to meet as a registrar?

    Would you like to be able to register domain names for customers or for your own organisation by dealing directly with SIDN? If so, you can become a .nl registrar. Read more about the conditions and how to apply for registrar status on the page becoming a registrar.

More frequently asked questions

Developers want to clean up DNS software code

"Nearly a quarter of the code is now for workarounds and corner cases"

  • Wednesday 30 January 2019

DNS resolver software developers have named 1 February 2019 as DNS Flag Day. That's the day when they'll start withdrawing software support for DNS servers that don't work correctly. The main providers of public DNS services (Cisco Umbrella, Cloudflare (1.1.1.1), Google Public DNS, Quad9 (9.9.9.9) and CleanBrowsing) are supporting DNS Flag Day as well, so domains with problematic DNS servers may become unreachable after 1 February.

The servers in question are those running outdated software, which doesn't support the EDNS extension to the DNS protocol. However, the problem that DNS software developers want to address is broader: over the decades, their code has been extended so much that it's becoming an issue. Further code clean-up initiatives can therefore be expected in the future. 

Registrants and operators need to test for EDNS compliance

Workarounds

"Nearly a quarter of our code is there to facilitate workarounds and corner cases," says Benno Overeinder, CEO of NLnet Labs, responsible for the development of the Unbound resolver. "The current situation has a long history. When EDNS was introduced -- mainly to support DNSSEC -- we were obliged to add code in order to continue communicating with servers that hadn't implemented the DNS protocol correctly or fully. It was all about ensuring that the product met the user's needs. However, it meant that we were picking up the tab for things that other people should have done.

"Over the last five or six years, the DNS software development community has come around to thinking that we can't go on this way. Last year, that led to an initiative from CZ.NIC, the registry for the Czech .cz country-code TLD and developer of the Knot DNS server. Their idea was to get a joint strategy agreed. After all, interoperability is an issue for the entire DNS community, not just for developers." 

Peter van Dijk, Senior Engineer at PowerDNS, explains the practicalities of realising a resolver workaround for non-compliant DNS servers: "If we don't get a response from a server because it can't handle EDNS queries properly, first we simply try again. If there's still no response, we try an alternative name server. The problem there is that all of a given domain's servers are often running the same software. So then we have to try the query with various EDNS flags disabled. And, if all else fails, we send a query that doesn't include any EDNS flags at all. That whole process easily takes ten seconds or more and involves sending numerous network packages. What's more, having all the workarounds makes the code complex and harder to maintain, which in turn has security implications."

Corner cases

As well as practical workarounds to keep everything going, resolver software includes 'corner cases': protocol-level interactions, interpretations and exceptions. They're needed because internet protocols often continue developing for several decades. Over time, a standard that began as an extremely elegant solution is modified repeatedly to address unforeseen issues and new developments, until it becomes a complex patchwork.

Nearly a year ago, Bert Hubert, founder of PowerDNS, wrote a blog post warning about the growing complexity of the DNS and the interactions between entities. That makes software development and maintenance more difficult, with knock-on implications for the stability of the infrastructure, the diversity of the ecosystem and the scope for innovation. He identified DNSSEC and NSEC3 as important drivers of complexity and the need for interpretation. Hubert ended his post by calling for the community to take a cautious approach to the addition of new features and standards, and to involve software developers and operators more in the design process.

Test your name server

Ahead of DNS Flag Day, registrants and operators are advised to check their domain names (or, more precisely, their name servers) for EDNS compliance. To do that, you can visit the DNS Flag Day homepage and use ISC's EDNS Compliance Tester [1, 2].

In recent weeks, SIDN Labs has been looking closely at this problem. That has led to various .nl domain name operators being alerted to issues, which they have since addressed. As a result, DNS Flag Day's impact on the .nl zone is expected to be minimal.