We pick h.root-servers.net, one of the 13 root servers (1), and ask it about nude.hu and learn that hu is delegated to seven name servers (2), so we ask e.hu where we learn that nude.hu is delegated to two name servers, including ns2.ridiss.com (3), so we ask that one and get the following answer:
The two name servers ns and ns2.ridiss.com together
There are seven domains that use name server group 2.
Two of those point only to the IP number 193.34.134.131. Worth noting is that two of the host names that point only to the IP number 193.34.134.131 use name server group 2.
All of the one domains that only use the mail server mail.nude.hu use name server group 2. Worth noting is that one of the domains that use name server group 2 use only the mail server mail.nude.hu.
The mail server mail.nude.hu
All of the one domains that use the mail server mail.nude.hu use only the mail server mail.nude.hu.