Linux – HOSTALIASES with Fully qualified domain names

There is a way to do this, but it is unreliable and requires a service provider to manage a database.

One example is at DomainTools

Basically, someone with access to lots of network traffic records domain name resolutions and aggregates them into a searchable database. This will only work with routable IP addresses, so if you are trying to do this on a large internal network, tools like this one will not help you.

Note that this is NOT comparable to a reverse DNS query. A reverse DNS query is RFC sanctioned functionality and there are many tools for performing those lookups. That is something to keep in mind when communicating your intentions to other network folks.

You're learning why you shouldn't use the same domain name for your Active Directory as you're using for your external Internet presence.

The "A" records for the domain referring to the domain controllers are used for DFS to resolve the name of the domain to a domain controller (primarily for client computers to access the SYSVOL). If you delete those "A" records you're going to see group policy break, amongst other things.

If you can't rename the AD domain, I think you're stuck putting IIS (or some other HTTP server) up on those boxes to redirect client computers to the right host.

This is why I name my AD domains "ad.domain.com". You should have a really, really good reason before you create a DNS zone on a private DNS server that matches a zone that the Internet has authoritative DNS servers for already. You've done that, and added Active Directory into the mix.