I read in easyDNS that, in order to set up reverse DNS, "The IP block must be delegated to our nameservers by your ISP." Is that always the case? What if you decide to host your name servers? Will adjusting the PTR records suffice? Some discussions on the web lead me to think that it isn't.
After these boolean questions (in particular if the answers are negative), please feel free to elaborate the DNS 101 concepts behind them. In my no-background mind, it looks like you are "given" that IP address (say, by your VPS hosting company), and that you should be able to "tell the world" that, having reached that IP, it corresponds to domain example.com.
Thanks!
Best Answer
It depends on the provider and its policies. Normally, you will not delegated reverse DNS authority without you having some large block of continuous IP space. If it's just normally one to eight IPs, you won't get control over it. In that case the ISP will handle reverse DNS.
In most hosting situations you must send in a support ticket to contact the ISP/Upstream/Datacenter/Etc to update the PTR record. But, some providers, like Softlayer, allow you modify it yourself via a control panel.