Since the IP address is under the control of your ISP or upstream connectivity provider, you will need to have the delegation done by them rather than through the registrar of the domain you are pointing it to. Unfortunately the delegation of IP addresses is not as standardised as the delegation of domain names. Different companies will delegate according to different standards and will need to let you know how they will delegate to us so we can set things up compatibly. There are 4 delegation standards we support. They are: RFC-2317, RFC-2317 Modified, IP Range, and First IP. When you setup reverse dns using easyDNS you will indicate the applicable method using the user interface shown below.