Do all registered domains have domain name servers assigned to them?
If I just want to know if a domain name is reserved; is it enough to use this command and see if any domain name servers come up, in which case it is reserved?
host -t NS example.com
This is much faster than visiting http://www.internic.net/whois.html and typing example.com to get much more verbose results that I'm not interested in anyway.
Different TLDs have different requirements to ensure that there are nameservers or not. For example, ".de" requires the nameservers to be up and running and configured correctly before they can proceed with domain registration.
The technical standards for DNS do not require this, although in fact there is no reference in the core DNS specifications to the relationship between the registration of a name and its subsequent operation in the DNS.
Therefore, using whois
is probably the most reliable method, with the caveat that you need a whois client that is smart enough to figure out which server to talk to for a given domain.
However, checking the corresponding NS record is a very good shortcut to verify that the domain is registered, you simply cannot use the absence of such a record to prove that it is not!
source to share
Absolutely not.
A previous employer registered his .biz name exclusively for use on the internal network: he had DNS records on the internal DNS server of the network, but nowhere on the Internet.
I'm not sure if the trick was particularly important, but "imap.theirname.biz" has the advantage over "imap" that it is unambiguous if you are connected to multiple networks at the same time (assuming no intentional foul of course), so you can just use all their internal DNS resolutions. Also the advantage over "imap.theirname.com" is that once you know the agreement, it is immediately obvious that this is a private server, and therefore the reason you cannot connect to it is because you forgot connect VPN. Perhaps there were other advantages that I was not privy to: I am a coder, not an IT technology ...
source to share