Adding Conditional Forwarder through GUI fails

Question

I've migrated some IPv6 reverse lookup zones from my Server 2019 DNS and try to replace them with conditional forwarders, pointing to the new server (Bind9/Debian10 if that matters).
Using DNS Manager I create a new conditional forwarder for the ...ip6.arpa domain and enter the new server's FQDN. DNS Manager does some validating and says for IPv6 "No IPv6 address was found for the DNS name entered" and for the resolved IPv4 address just "Validating...". If I enter the IPv4/6 addresses it says "An unknown error occurred while validating the server".
I checked everything, using nslookup on the 2019 DNS server. DNS seems to work as it should, so I finally resorted to PowerShell and that works.

But I'm still a little bit concerned: DNS is pretty important, so if there are any issues in my system I'd like to fix them. So what exactly is DNS Manager validating?

Answer 1

Hi ,

Using DNS Manager I create a new conditional forwarder for the ...ip6.arpa domain If I enter the IPv4/6 addresses it says "An unknown error occurred while validating the server".

If NSlookup works fine, the result of validation should not affect forward function. When DNS server forwards query to the remote DNS server, it refer to the IP address of the remote server.

You can try to trace network traffic when you are adding conditional forwarder through GUI and adding conditional forwarder via PowerShell. Compare the network packets, when you add a forwarder, the server will query for the PTR record, then send SOA query to the remote server. If the remote server receives the packet, it will send back “response-success” packet.

If there is no problem with network packet, I would suggest you ignore the validation error in DNS manager.

In addition, please understand, analysis of network traffic is beyond our forum support level and due to forum security policy, we have no such channel to collect user log information. If you want to find the root cause and get a more satisfying explanation to this issue, I would suggest you open a case with MS Professional tech support service, they will help you open a phone or email case to Microsoft, so that you would get a technical support on a one-to-one basis while ensuring private information.

Here is the link:

https://support.microsoft.com/en-us/gp/customer-service-phone-numbers

Best Regards,
Candy

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