That would be true if the traffic was originating from the host/dns entry. But if the host just serving it shouldn't be necessary. Well atleast I can't find a reason. Outside of this confusion I have, let me explain my dilemna.
I have control of my domains dns records through my web host. I want to add entries within dns that points back to servers on my local dmz. I know there is no issues with the forward lookup because it will ultimately query my dns to resolve. My problem is where do I set the reverse entry? My web host or my ISP?