You can use nslookup on the IP. Reverse DNS is defined with the .in-addr.arpa domain. Example: nslookup somedomain.com yields 123.21.2.3, and then you do: nslookup 123.21.2.3 this will ask 3.2.21.123.in-addr.arpa and yield the domain name (if there is one defined for reverse DNS).
You can try querying the ripe database http://www.db.ripe.net/whois
Proper way to do it: Change the zone TTL to minimum – in most cases it’s 300 seconds (5 minutes). Do not change any records at this stage. Wait 48 hours. Do the change. It will take just 5 minutes to propagate the changes. Revert TTL to standard 48 hours. This procedure applies to all … Read more
There are several well-known ways of locating whois servers for TLDs, the IANA database is probably the closest to what the question asks for, however there are other sources that may be more useful in practice. From IANA (access via whois and http) Browse http://www.iana.org/domains/root/db or search the whois database at whois.iana.org for the TLD. … Read more
Why are these domains allowed to not have whois information? Is this something that anyone can access, for privacy protection? TLDR: It’s not the case that these domains have somehow obtained an exemption from ICANN that allows them not to omit certain data from public WHOIS records. It’s more likely the case that the WHOIS … Read more