Configure Windows to use a DNS server on the TAN network

In order to use a DNS Server that is connected via the TAN network, it is necessary to make some adjustments to the network interfaces.

The basic idea is to promote the connect network interface, in favour of the physical network interface, by raising the metric of the physical network interface.

This guide will take you through setting the DNS server and setting the network metric.

Setting the DNS server and network metric

Open Control Panel

In the taskbar, type Control Panel and select the Control Panel App, which is likely the top result:

Select Network and Sharing Centre

Click on Network and Sharing Centre

Select Network and Internet

Click on Network and Internet

Select the Physical Network Interface

Select the physical network interface; this will generally be either Ethernet or Wifi.

Select the Network Interface Properties

Select the network interface properties

You may be asked to enter a username and password in order to elevate to Administrator privileges.

Select Internet Protocol Version 4 properties

Select Internet Protocol Version 4 (TCP/IPv4) and then click Properties.

Set the DNS server address

Set the Preferred DNS server address to the address of the TAN endpoint and click on Advanced....

Set the interface metric

Deselect Automatic metric and enter an interface metric of at least 15.

Click OK to apply the metric setting, and again to apply the DNS server address setting.

Testing DNS look-up

• Start a new Command Prompt, Powershell or Windows Terminal session
• Run nslookup:

  > nslookup
  Default Server:  UnKnown
  Address:  100.94.236.51
  
  >
  

• Type a domain name:

  > google.com
  Server:  UnKnown
  Address:  100.94.236.51
  
  Non-authoritative answer:
  Name:    google.com
  Addresses:  2a00:1450:4009:817::200e
            172.217.169.14
  

If the DNS query is still not being resolved, see Disable IPv6 below.

Disable IPv6

It may be necessary to disable IPv6 on both the physical network interface and on the connect network interface.

Follow the steps from Setting the DNS server and network metric until you are at the Network Interface Properties, and uncheck Internet Protocol V6 (TCP/IPv6).