Where does the whois command get its information from?

Question

Usually, I go to whois.icann.org to find domain names, but there are limits to the number of searches I can do, and I sometimes have to solve captchas.

There doesn't seem to be such limits with the whois command. Where does the whois command get all that whois information from?

Possible duplicate of [What are the limits of whois command on unix?](http://superuser.com/questions/452751/what-are-the-limits-of-whois-command-on-unix) — , Feb 04 '17 at 21:43
There is a comment at that other question that alludes to where the whois information comes from, but it is not explicitly stated. This question is specifically about WHERE the information returned by unix' whois command comes from. At the same time, I'd imagine that answer is an easy google search away as it is likely well documented: https://www.google.com/search?q=where+does+unix+whois+information+come+from&ie=utf-8&oe=utf-8 — music2myear, Feb 07 '17 at 18:00

score 1 · Accepted Answer · answered Dec 11 '16 at 11:48

whois queries a very large, and very different, set of registers depending on the domain name. You can get a simple idea of how many by means of

strings /usr/bin/whois | grep whois

On my Debian, this results in 261 different subdomain registers. It turns to whois.networksolutions.com only when all other options have been exhausted.

You can answer that question more precisely by downloading the original code,

mkdir tmp
cd tmp
sudo apt-get source whois
cd whoisXXX

and then you have all the servers to be contacted listed in several files, free for you to peruse.

score 0 · Answer 2 · answered Dec 11 '16 at 10:19

On Linux whois have different options "man whois" .

As in the description ( Debian jessie) it uses it will connect to whois.networksolutions.com for NIC handles or whois.arin.net . It is explained as followed:

DESCRIPTION whois searches for an object in a RFC 3912 database.

   This version of the whois client tries to guess the right server to ask
   for the specified object. If no guess can be made it  will  connect  to
   whois.networksolutions.com  for  NIC handles or whois.arin.net for IPv4
   addresses and network names.

Where does the whois command get its information from?

2 Answers2