We pick a.root-servers.net, one of the 13 root servers (1), and ask it about norid.no and learn that no is delegated to six name servers (2), so we ask i.nic.no where we learn that norid.no is delegated to four name servers, including server.nordu.net (3), so we ask that one and get the following answer:
Norid.no is a domain controlled by four domain name servers at nordu.net, uninett.no and nac.no having a total of eight IP numbers. Some of them are on the same IP network. Incoming mail for norid.no is handled by two mail servers at uninett.no having a total of two IP numbers. Two mail servers have the same IP number. Both are on different IP networks. Norid.no has two IP numbers (2001:700::4513:158:38:130:37, 158.38.130.37). Both are on different IP networks.
Five of them point to the IP number 158.38.130.37. Worth noting is that five of the host names that point to the IP number 158.38.130.37 use the mail server dike-ac.uninett.no.
There are eleven host names that point to the IP number 158.38.130.37.
Five of those use the name server nac.no. Worth noting is that three of the domains that use the name server nac.no point to the IP number 158.38.130.37.