ns2.rus.ru has one IP number , but the reverse is ns4.ripn.net. viufa.ru, marsat.ru, ns3.li.ru, mpei.ac.ru, belonex.ru and at least 63 other hosts point to the same IP. rus.ru use this as a nameserver. rus.ru is a domain controlled by three nameservers at rus.ru themselves. All of them are on different IP networks. Incoming mail for rus.ru is handled by two mailservers also at rus.ru. They are on the same IP network. rus.ru has one IP number. ns2.rus.ru is hosted on a server in Russian Federation.