A Windows 10 computer on my network has a fully-functional IPv6 connection, but always prefers IPv4 when available. http://test-ipv6.com/ in Edge, Firefox, and Chrome reports "Your browser has real working IPv6 address – but is avoiding using it. We're concerned about this." I've never set this up this way, and I can't find any settings that would be causing it. Other computers, both Windows and Linux, exist on the same network but don't have this problem. In the Registry, under HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters, neither EnableICSIPv6 nor DisabledComponents exist, and this is the case both on this computer and on a properly functioning Windows 10 computer. What could be causing this, and how can I fix it?
Windows – is the Windows 10 computer preferring IPv4 over working IPv6
ipv6networkingwindows 10
Best Answer
As far as I know, by default, Windows prefers IPv6 over IPv4.
>In the Registry, under HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters, neither EnableICSIPv6 nor DisabledComponents exist. If the registry entries do not exist, you can manually add them.
You can fix it using the tool provided by Microsoft, or, manually editing the registry entries.
Details steps you may reference KB 929852 - How to disable IPv6 or its components in Windows: https://support.microsoft.com/en-us/help/929852/how-to-disable-ipv6-or-its-components-in-windows
Best Regards, Eve Wang