How to Setup DNS Conditional Forwarder for Subdomains on Windows 2019 Server

Around a week ago I redid my lab network and added 2 new domain controllers. I used one of my website domains as the lab domain to mimic how a corporation could be setup.

So the domain for my network was “voltdrift” and the website domain is externally hosted with the domain of “www.voltdrift.com

The Problem: DNS will not resolve subdomains.

Ones I was done I noticed I could not get to the website. The DNS on the domain controller would not resolve it. I thought I knew how to fix this and all I needed was a new delegation for the “www” subdomain. I could have sworn that’s how I did it on Windows Server 2012 but for some reason, it would not work in Windows Server 2019.

DNS Conditional Forward

So after a few hours of messing with it off and doing some reading, it seemed like a “Conditional Forward” was what I needed. But there was a problem. When I tried to add one I got this error.

“A problem occurred while trying to add the conditional forwarder. A zone configuration problem occurred.”

 conditional forward error

It seems that because my local domain is “voltdrift” the domain controller / DNS did not want to add any conditional forward rules dealing with that domain.

The Work Around

The way to get around this error is to trick the DNS server into thinking it is not in control of that domain/subdomain. Or at least that’s how I understand it. We do this by adding a new delegation to the DNS server for that subdomain.

delegated domain name

Then we point that delegation to our Domain Controller / DNS server. I know it seems kind of silly. I have 2 so in my case, I pointed it to both of them.

name server
name server

Now we can setup a new conditional forward without the error.

new conditional forward

Make sure you check that box if you want the conditional forwards to replicate to all your other DNS servers.

Now the conditional forward works

Now you’re DNS should be able to resolve your website under the subdomain www.

I still feel like this was easier in the past but this is how I got it working on a Windows Server 2019 DNS. So I thought it would be a good idea to document the process. I hope it has helped you!

If you know of a better way please let me know in the comments below! I’d love to hear about it.

Ref: Conditional Forward Rules and Subdomains – Sysjolt