We pick a.root-servers.net, one of the 13 root servers (1), and ask it about j.ua and learn that ua is delegated to six name servers (2), so we ask pch.ns.ua where we learn that j.ua is delegated to two name servers, including ns1.prostir.net (3), so we ask that one and get the following answer:
J.ua is a domain controlled by two domain name servers at prostir.net. Both are on different IP networks. Incoming mail for j.ua is handled by one mail server also at prostir.net. J.ua has one IP number (213.186.117.110), but the reverse is prostir.net.
There are five domains that use the mail server prostir.net.
All of those point to the IP number 213.186.117.110. Worth noting is that five of the host names that point to the IP number 213.186.117.110 use the mail server prostir.net.
Two thirds of them use the name server ns1.prostir.net. Worth noting is that a third of the domains that use the name server ns1.prostir.net point to the IP number 213.186.117.110.
The two name servers ns0 and ns1.prostir.net together
A third of the about fourty domains that use name server group 1 point only to the IP number 213.186.117.11 (example: dekor.in.ua and bau.com.ua ).
The IP number 213.186.117.110 only
There are about twenty host names that point only to the IP number 213.186.117.110.