The Purpose of DNS Sub-Delegation
Let’s say you have acquired a static IP range from your ISP. Now that you have that range, you decide you also want to control the PTR
records for these addresses as well. But, PTR
records typically belong to the ISP. However, you do not want to depend on the ISP for each change you’d like to make; you want more control. How can your gain more control over those PTR
records?
The way to gain this control is through DNS Sub-Delegation. DNS Sub-Delegation is when your ISP forwards PTR
requests to your name server so that you can have control over your record updates. In other words, the ISP delegates their authority over their PTR
records to your DNS server.
Prerequisites
If you understood the implications of that last sentence, you’ll realize that you will need your own local DNS service that controls your domain. After all, if you don’t control your own domain, how are you going to control the PTR
records once they are delegated to you? In this post, we’ll assume that you will manage your PTR
records with your own DNS server. Continue reading How to Sub-Delegate Reverse DNS Records Part 1 →