Prevent DNS and IPv6 Leaks In Windows 10
Windows 10 has provided several challenges when using a VPN in keeping DNS and other information from leaking past the VPN connection.
In many cases the VPN connections are less secure than believed because DNS data is passing outside the VPN connection or over the IPv6 pathway.
In other cases IPv6 prevents traffic from passing over the VPN.
There are three steps in ensuring that this does not happen to you.
1: ( if you are using OpenVPN) Be sure your VPN provider is using the OpenVPN feature that blocks outside DNS. If not, get them to add it to their configuration or find a different provider. This feature was specifically implemented by OpenVPN in response to Windows 10 issues.
2: Change your DNS to public outside servers instead of using the ones your local network or ISP points you to.
Here are some options:
Google - 184.108.40.206
Open DNS - 220.127.116.11
SurfBouncer DNS - 18.104.22.168
CloudFlare - 22.214.171.124
Quad 9 - 126.96.36.199
3: Disable IPv6.
There are several ways to do this. The first is from the Command prompt.
Open A Command Prompt as administrator by right clicking on cmd and selecting Run as Administrator (search for cmd if you don't know how to get there directly)
In the black command box that appears type or copy and paste exactly the following:
reg add hklm\system\currentcontrolset\services\tcpip6\parameters /v DisabledComponents /t REG_DWORD /d 0xFFFFFFFF
Press enter and reboot the computer.
An easier way is to use the procedures and software Microsoft provides to do it from here. However this requires downloading the software from Microsoft.