From: Matt Chung [mailto:itsmemattchung@gmail.com]
Historically, there was no compelling reason to create PTR records for our CPE however more and more applications seem to be dependent on it. Although we will be assigning a record for each address, my question is why is the application (specifically HTTP) dependent on a reverse record ? What is the purpose?
As a web host, we frequently find customers who have added Apache rules to their ecommerce sites to block undesirable traffic, such as credit card scammers, etc. Not knowing any better, they often do this by just blocking anything that ends in .in to block Indonesia for example. Well, once you choose to block by resolved name, now that site has to do a dns lookup for every incoming request to see if it resolves to a name that should be blocked. Just one example, but I'm sure there are countless others that also impede performance for IP addresses without a PTR record. David