ns1.tidi.nl has one IP number , but the reverse is shell1.tidi.nl. shell1.tidi.nl point to the same IP. bgzc.nl, swwg.nl, axel.nl, devey.nl, ovet.net and at least 100 other hosts use this as a nameserver. tidi.nl is a domain controlled by three nameservers. Two of them are on the same IP network. Incoming mail for tidi.nl is handled by two mailservers at tidi.nl themselves. They are on different IP networks. tidi.nl has one IP number. ns1.tidi.nl is hosted on a server in Netherlands.