We pick d.root-servers.net, one of the 13 root servers (1), and ask it about hixp.de and learn that de is delegated to six name servers (2), so we ask a.nic.de where we learn that hixp.de is delegated to two name servers, including ns1.parkingcrew.net (3), so we ask that one and get the following answer:
Hixp.de is a domain controlled by two domain name servers at parkingcrew.net. Both are on different IP networks. Hixp.de has one IP number (62.116.143.10), but the reverse is ?.