Technical details on the domain information

How do we find the right whois server

Domains

We first rely on the DNS, which is the safest method. We query the SRV records (see RFC 2782 ) "nicname", as described in The Internet-Draft "Using DNS SRV records to locate whois servers".

Then, we ask the IANA database which lists some whois servers.

Then we try whois.nic.$TLD.

IP addresses

We always query ARIN first, since it seems to be the only RIR which includes proper redirections.

Getting a pure text output, without HTML

Just request http://www.generic-nic.net/dyn/whois/ask-text?query=YOURDOMAIN. This would yield a reply of type text/plain, suitable for tools like wget, for instance.

Presentation

You have three ways to format the text output of a whois server.

As a pre-formatted text (like you show computer programs)

It is the solution we currently use.

Pros:

• Simple to program
• Faithful to the original output

Cons:

• Not pretty
• The labels can be unclear (no standard ontology)

Translate to HTML with a standard program

I tried this approach with Perl's TextTOHTML module.

Pros:

• Quite simple to program, unless you start patching the programs for special cases
• Sometimes quite pretty

Cons:

• Special cases are really painful and can lead to really ugly outputs
• The labels can be unclear (no standard ontology)

Parsing to high-level objects and serialization as HTML

A former whois service at AFNIC worked that way.

Pros:

• Consistent with the future CRISP appproach
• Standard ontology and vocabulary, you can adapt it to the reader (for instance, translating it in other languages)
• Very pretty (and consistent)

Cons:

• By far the most complicated to program (even with tools like XWhois or Gandi::WhoisExtract) and to maintain, since the output formats can change.
  It can be easier with registries like Adam's Names, which have information systems based on Web services
• Since you haver to translate everything to your pivotal ontology, you may lose subtle semantic details

Software we use

This service was developed with the Perl programming language, the Mason templating system.

The interaction with the whois servers is performed by a custom Perl package (available on demand).

Warning: results sent by this service comes directly from foreign whois servers that we do not control. That's why they can be in many languages, for instance.

(French) Attention : les résultats affichés par ce service viennent directement de serveurs whois étrangers que nous ne contrôlons pas. C'est pourquoi ils peuvent être dans des langues différentes.

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