As a hosting provider however, Leaseweb is simply huge in the industry. It is a global top-10 player, which made it interesting for us to have our routing technology hosted by them.


The organization
As a registry, SIDN ( is responsible for the stable and secure operation of the .nl domain. This market-independent organization registers .nl domain names and makes sure that the domain names are easily accessible. With more than 5 million domain names, the .nl domain is the fifth largest country domain in the world. The organization employs around 80 people.
One of the founders of SIDN is Internet pioneer Piet Beertema, who in 1986 was given a country domain for the Netherlands by the American Internet pioneer Jon Postel. Following a sharp rise in the number of Internet users in the Netherlands, SIDN was established to professionally handle the registration and management of the .nl domain.

Key requirements

  • Mitigate the negative effects of DDoS attacks
  • Improve security and accessibility of .nl domain
  • Placing SIDN’s DNS Anycast technology “in the field”
  • Qualifying criteria for market participants: business volume + BCP 38 best practices

The request
In 2013, SIDN noted an increase in Distributed Denial of Service (DDoS) attacks. The ferocity of these attacks concerned SIDN. To proactively mitigate the negative effect these developments might have on the .nl domain, SIDN decided to have its DNS anycast technology distributed “in the field” by Internet-related parties willing to do so, such as telecommunications and hosting providers.

Whereas Domain Name System (DNS) technology is used to translate computer domain names into numerical IP addresses and vice versa, DNS Anycast technology is a method to make DNS records available on a duplicated and geographically distributed basis, which enhances availability. SIDN is the first registry in Europe to lend added protection to a national top-level domain (TLD) and enhance availability by also having Internet-related parties integrate this technology into their IP networks.

Leaseweb was the first market participant to be approached by SIDN because of the size of the hosting company and the scope of the state-of-the-art network.

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Even though Leaseweb is a major hosting provider with an international presence, everything was arranged very quickly — Marc Groeneweg


The solution
Leaseweb made the required data center facilities available free of charge by means of a zero-euro contract. In addition to a fully-fledged .nl name server, the DNS Anycast technology delivered to Leaseweb also includes a switch, a firewall, plus a node. In order to install the technology, Leaseweb made colocation rack space at one of its Dutch data centers available to SIDN, including redundant power supply, network access, and 1 Gbps capacity on a state-of-the-art worldwide IP network. The technology is directly linked to the IP backbone.

Since then, five other major Internet companies have also responded favorably to SIDN’s request to implement the DNS Anycast technology locally. SIDN also found eight Internet companies willing to make a Border Gateway Protocol (BGP) link with SIDN via Internet exchange AMS-IX. However, the market participants approached by SIDN are required to comply with a number of qualification criteria and technical requirements. For one thing, like Leaseweb, they need to have substantial scope.

The local presence of SIDN’s DNS anycast technology with market participants such as Leaseweb significantly enhances the availability of the .nl domain. Imagine SIDN’s .nl service is affected by DDoS attacks; for Leaseweb customers the .nl domain will remain available as normal thanks to this local routing technology. This means that a substantial part of the business market in the Netherlands is not affected, and can continue to make uninterrupted use of the .nl domain.