pdns1.cscdns.net has one IP number , which also has a corresponding reverse pointer. ns1.fileburstcdn.com point to the same IP. fr.com, lr.org, bd.com, pm.com, jet.nu and at least 100 other hosts use this as a nameserver. cscdns.net is a domain controlled by two nameservers at cscdns.net themselves. They are on different IP networks. Incoming mail for cscdns.net is handled by two mailservers at cscinfo.com. They are on the same IP network. pdns1.cscdns.net is hosted on a server in United States.