sidnAnother Question and Answer. This time with the Foundation who regulates and manages the registry of the .nl CCTLD SIDN.

Were talking with Marco Davids, Senior IT Specialist – SIDN ICT Operations & Support.

Please tell us a little about SIDN

SIDN is responsible for the functional stability and development of the
.nl Internet domain. As well as registering and allocating .nl domain
names. The organisation enables Internet users all over the world to
make use of these labels at any given moment.

SIDN’s rapidly growing domain name register now contains more than 3.4
million .nl domain names. In consequence, SIDN is a key player in the
global Internet community. The organisation’s services are provided to
the public through a network of two thousand independent commercial
Internet service providers, the so called registrars.

SIDN also plays an active role in the technical, regulatory and
political development of the Internet, at the national and international
levels. Through the ENUM Foundation for the Netherlands, SIDN is
additionally at the forefront of preparations to bring ENUM to the

Formed in 1996, SIDN is based in the Dutch town of Arnhem, where it
employs a little over fifty people.

Corporate website:

When and how did IPv6 began to be a part of SIDN

IPv6 experiments started around 2001 in a testbed environment with
tunnels towards SURFnet, the Dutch academic network. Later, the first
nameservers that are authoritative for the .nl zone where upgraded to
support IPv6. In 2005 the SIDN backbone was fully upgraded to support
native IPv6, be it with IPv6 address space that was aquired from
SURFnet. At about the same time the Domainname Registration System (DRS)
was adapted to support IPv6 glue addresses. Soon after that an
increasing number of IPv6 glue addresses appeared in the .nl zonefile.

What is the current status of IPv6 at SIDN

SIDN has aquired it’s own IPv6 space from RIPE and is gradually
deploying that in their backbone. Also more nameservers are reachable
via IPv6. At this moment 4 out 7 nameserver instances for .nl support
IPv6. For the ENUM zone it is 1 out of 3. The plan is to
increase these numbers as soon as possible.

Furthermore a few of the corporate websites are reachable via IPv6
nowadays. Like for example The main site, will be reachable over IPv6 before the end of 2009.

The next step is to disclose other services via IPv6, like for example
te WHOIS service and the EPP interface, once it becomes available.

In september 2006 we counted 19 IPv6 glue addresses in the .nl zonefile
(compared to 21.369 IPv4 addresses). Today we count 112, compared to
24.874 IPv4 glue addresses.

IPv6 traffic on the .nl nameservers is also increasing slowly, but

In what way do you expect to see IPv6 growth in the next couple of years for SIDN?

Once IPv4 addresses are exhausted, more and more people will start to
use IPv6. All signs point in that direction. SIDN intends to be fully
prepared when that happens. Way in advance.

Are there any things you would like to say about IPv6 in general?

IPv6 is no rocket science. All major vendors support it in a way that is
suitable for production. And IPv4 space is indeed running out. Really,
it is. Today is the day to start looking into IPv6, if you haven’t

already done so. It will save you a steep, stressful learning curve once
the pressure to switch becomes higher.

Have a look at for further information.

Also, if you intend to buy new equipment, make sure it supports IPv6.
This should be a requirement for anything you buy from now on.

Thanks go out to Marco for making some time to answer our questions!