We pick m.root-servers.net, one of the 13 root servers (1), and ask it about yahoo.mobi and learn that mobi is delegated to six name servers (2), so we ask a0.mobi.afilias-nst.info where we learn that yahoo.mobi is delegated to five name servers, including ns3.yahoo.com (3), so we ask that one and get the following answer:
Yahoo.mobi is a domain controlled by five domain name servers at yahoo.com. All five of them are on different IP networks. Incoming mail for yahoo.mobi is handled by one mail server at .. We are missing the IP:s of one server: .. Yahoo.mobi has two IP numbers (68.180.206.184, 98.139.102.145). Both are on different IP networks.
The five name servers ns1, ns2, ns3, ns4 and ns5.yahoo.com together
Two thirds of the several thousand of domains that use name server group 1 point to the two IP numbers 68.180.206.184 and 98.139.102.145 together, hereafter referred to as "IP group 1", (example: httpwwwyahoomail.com, video-gamesyahoo.com and groupsyahoo.net ). Worth noting is that three quarter of the host names that point to IP group 1 use name server group 1.
The IP number 68.180.206.184
There are several thousand of host names that point to the IP number 68.180.206.184.