We pick l.root-servers.net, one of the 13 root servers (1), and ask it about eunet.sk and learn that sk is delegated to seven name servers (2), so we ask ns3.sk-nic.sk where we learn that eunet.sk is delegated to three name servers, including ns.ew.sk (3), so we ask that one and get the following answer:
Eunet.sk is a domain controlled by three domain name servers at ew.sk. All three of them are on different IP networks. Incoming mail for eunet.sk is handled by one mail server at euroweb.sk.
The two name servers ns.ew.sk and ns.ttx.sk together
Six of the about twenty domains that use the two name servers ns.ew.sk and ns.ttx.sk together, hereafter referred to as "name server group 2", point only to the IP number 193.110.187.3 (example: inpool.sk and tomnet.sk ).