blog.dubr.net has one IP number , which is the same as for dubr.net, 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. dubr.net is a domain controlled by two nameservers at pipni.cz. They are on different IP networks. Incoming mail for dubr.net is handled by two mailservers on different IP networks. blog.dubr.net is hosted on a server in Czech Republic.