We pick m.root-servers.net, one of the 13 root servers (1), and ask it about vnnic.net.vn and learn that vn is delegated to seven name servers (2), so we ask c.dns-servers.vn where we learn that vnnic.net.vn is delegated to three name servers, including dns2.vnnic.vn (3), so we ask that one and get the following answer:
Half of them use the three name servers dns1, dns2 and dns3.vnnic.vn together, hereafter referred to as "name server group 1".
The name server dns3.vnnic.vn
There are about twenty domains that use the name server dns3.vnnic.vn.
All of those use name server group 1.
Half of them point only to the IP number 203.119.8.85.
Four of them use the two mail servers mailgw1 and mailgw2.vnnic.vn together, hereafter referred to as "mail server group 1".
The name server dns2.vnnic.vn
There are about twenty domains that use the name server dns2.vnnic.vn.
All of those use name server group 1.
Half of them point only to the IP number 203.119.8.85.
Four of them use mail server group 1.
The name server dns1.vnnic.vn
There are about twenty domains that use the name server dns1.vnnic.vn.
All of those use name server group 1.
Half of them point only to the IP number 203.119.8.85.
The three name servers dns1, dns2 and dns3.vnnic.vn together
There are about twenty domains that use name server group 1.
Half of those point only to the IP number 203.119.8.85. Worth noting is that half of the host names that point only to the IP number 203.119.8.85 use name server group 1.
Four of them use mail server group 1. Worth noting is that all of the domains that use mail server group 1 use name server group 1.
The IP number 203.119.8.85 only
Half of the about thirty host names that point only to the IP number 203.119.8.85 use name server group 1. Worth noting is that half of the domains that use name server group 1 point only to the IP number 203.119.8.85.
The two mail servers mailgw1 and mailgw2.vnnic.vn together
All of the four domains that use mail server group 1 use name server group 1. Worth noting is that four of the domains that use name server group 1 use mail server group 1.
The IP number 2001:dc8:0:2::84
There are five host names that point to the IP number 2001:dc8:0:2::84.