We pick b.root-servers.net, one of the 13 root servers (1), and ask it about autosapo.pt and learn that pt is delegated to eight name servers (2), so we ask auth210.ns.uu.net where we learn that autosapo.pt is delegated to two name servers, including ns2.ptm.pt (3), so we ask that one and get the following answer:
Autosapo.pt is a domain controlled by two domain name servers at ptm.pt. Both are on the same IP network. Incoming mail for autosapo.pt is handled by one mail server at sl.pt having a total of two IP numbers. Both are on the same IP network. Autosapo.pt has one IP number (213.13.145.87), but the reverse is superemprego.sapo.pt.
All of the five domains that use the name server ns2.ptm.pt use the two name servers ns and ns2.ptm.pt together, hereafter referred to as "name server group 1".
The mail server mail.sl.pt
All of the three domains that use the mail server mail.sl.pt use only the mail server mail.sl.pt.
The IP number 213.13.145.87
There are about thirty host names that point to the IP number 213.13.145.87.