Hey there! I'm running a Domain Controller that also serves as a DNS server. I'm trying to set up a forwarder to dns1.fortiguard.net by entering the IP address 96.45.45.45, but I keep getting a validation error in the GUI: "An unknown error occurred while validating the server." I've checked the name resolution using nslookup from the DC, and it works fine. I also tested the connection with PowerShell and it's successful on port 53. So, I'm confused about why the GUI says there's a validation error. By the way, my server is running Windows Server 2022, and I've tested the same setup on Windows Server 2019 and 2016 without any issues in the same network. Could this be a bug in Windows Server 2022?
2 Answers
It could be that the GUI is having a problem with the DNS forwarder setup. Instead of using it as a forwarder, have you tried adding it as a secondary DNS source on your DC? Sometimes, the GUI has quirks that can be bypassed with a different configuration.
It might be something simple! First, make sure that UDP Port 53 is open and that recursion is enabled on your DNS server. There are quite a few guides available on setting up Active Directory DNS and DNS forwarding if you need to double-check your setup. If you're combining multiple roles on one server, just take your time to ensure everything's set up correctly now, so you don’t face issues later on.
Have you confirmed that UDP 53 isn't being blocked by your firewall? If nslookup and other tests on 96.45.45.45 are working, then the issue must be elsewhere.