How to find domains registered at a certain time?

Question

Is there a place where you can reach the history of domain registrations?

To be more specific: How can I find out what other domains have been registered within a certain period of time?

I know there are paid services which allow you to find bulk-domain registrations. I wonder how they got those data.

thx in advance!

Answer 1

Typically they have an agreement with Whois registrars to obtain a dump of the database every night, and/or they run something like passive DNS to discover domains to put in their database.