ns.irib.ir has one IP number , but the reverse is ns1.irib.com. a.ns.tv2.ir, a.ns.tv4.ir, a.ns.tv1.ir, ns1.irib.ir, a.ns.tv3.ir and at least 36 other hosts point to the same IP. a.ns.irib.ir and b.ns.irib.ir are subdomains to this hostname. irib.ir is delegated to two nameservers, however both delegated nameservers are missing in the zone and two other nameservers are listed instead. There are two duplicated IP numbers. Some of them are on the same IP network. Incoming mail for irib.ir is handled by one mailserver at irib.ir themselves. irib.ir has one IP number. ns.irib.ir is hosted on a server in Iran.