We pick f.root-servers.net, one of the 13 root servers (1), and ask it about netnod.se and learn that se is delegated to nine name servers (2), so we ask g.ns.se where we learn that netnod.se is delegated to three name servers, including slave.gbg.netnod.se (3), so we ask that one and get the following answer:
Netnod.se is a domain controlled by three domain name servers at netnod.se themselves having a total of four IP numbers. All four of them are on different IP networks. Incoming mail for netnod.se is handled by one mail server also at netnod.se having a total of two IP numbers. Both are on different IP networks. Netnod.se has two IP numbers (22.214.171.124, 2a01:3f0:1:3::108). Both are on different IP networks.