DNS Forwarder - an unknown error occurred while validating the server.

Question

_{Thursday, August 20, 2015 3:37 PM}

Hello,

I am getting below error while adding the DNS Forwarder IP, when I click on edit and add the forwarder IP the error is coming, however I am able to add the same IP on other DNS server, i tried to resolve the IP using nslookup on same server and it is resolving...

Error Image : http://www.chicagotech.net/images/dnsissue4.jpg

An unknown error occurred while validating the server.

Need urgent help...

MCP, MCTS

All replies (1)

_{Friday, August 21, 2015 5:18 AM ✅Answered}

Hi Hi_SGH,

According to your description, when you add a DNS forwarder, unknown error occurs, but when you add the same IP address on other server, it works well.

We may perform a network traffic capture on the server that has problem and on the server works well, compare the packets when you add a DNS forwarder. In general, 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. We may check if the server with problem could receive the “response-success” packet from the remote DNS server.

Besides, the result of validation doesn’t affect forward function, when DNS server forwards query to the remote DNS server, it refer to the IP address of the remote server.

If you want to download network monitor to perform a network traffic, you may click the following link:

https://www.microsoft.com/en-us/download/details.aspx?id=4865

Best regards,

Anne he

Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact [email protected].