gw.expert.cz has one IP number , which is the same as for expert.cz, via cname , but the reverse is www2.pipni.cz. l.cz, 3am.cz, k28.org, enca.cz, hkcz.cz and at least 100 other hosts point to the same IP. expert.cz is a domain controlled by three nameservers at pipni.cz. Two of them are on the same IP network. Incoming mail for expert.cz is handled by two mailservers on different IP networks. gw.expert.cz is hosted on a server in Czech Republic.