I stumbled upon this tool recently: http://www.linkvendor.com/seo-tools/domains-from-ip.html How is it possible to find all domains listed for an IP? I mean, what's the technology behind it?
The function gethostbyaddr will give you the hostname of that IP, not all domains onthat IP. To make this tool, you have to start with a list of all domainnames and then use function gethostbyname, which returns the IP address of the Internet host specified by hostname.
So you would need a scanner that gets the ip from all the domains in the world? I'm pretty sure that's not what linkvendor is doing. That would be a huge job for a little tool like that.. wouldn't be worth it at all..
Making the tool with full info is not easy. Linkvendor is able to show only a small fraction of the websites. For a domain I checked, whois.sc showed 193 results, where Linkvendor showed only 72.
But still, how can I make something like that? It sounds crazy having spiders collecting data about all domains in the world..
domaintools premium membership has this feature. Its was free before and very useful, at least very interesting. It would be a nice tool on your site cypherus. I am ready to beta test it
The website robtex.com provides lot of interesting information, but does not specifically provide what the OP is looking for, i.e. find all domains listed for an IP.