dns1.4a.se has one IP number , but the reverse is helium.4a.se. ns3.itm.nu, linux.4a.se and helium.4a.se point to the same IP. 4a.se use this as a nameserver. 4a.se is a domain controlled by two nameservers on different IP networks. Incoming mail for 4a.se is handled by two mailservers at 4a.se themselves. They are on the same IP network. 4a.se has one IP number. dns1.4a.se is hosted on a server in Sweden.