dns1.cso.uiuc.edu has one IP number , which also has a corresponding reverse pointer. iu.edu, uwm.edu, niu.edu, iub.edu, oar.net and at least 100 other hosts use this as a nameserver. cso.uiuc.edu is a domain controlled by three nameservers. Two of them are on the same IP network. dns1.cso.uiuc.edu is hosted on a server in United States.