ns5.univie.ac.at has one IP number , which also has a corresponding reverse pointer. ns5.uibk.ac.at point to the same IP. co.ir, gv.at, id.ir, ac.ir, sch.ir and at least 100 other hosts use this as a nameserver. univie.ac.at is a domain controlled by five nameservers at univie.ac.at themselves. Some of them are on the same IP network. Incoming mail for univie.ac.at is handled by three mailservers also at univie.ac.at. All of them are on the same IP network. univie.ac.at has one IP number. ns5.univie.ac.at is hosted on a server in Austria.