Thomas SchäferDAD works, but nothing more.
Or in other words: At the moment it is not possible to use more than one Windows-PC with IPv6-mostly-support (Preview only ) in a IPv6-mostly or IPv6-only Network.
By accident a host may use one of the other mapped IPv4 addresses (out of 192.0.0.0/29) . But in general it takes the first one anywhere.
and W.B. is right: MS has to fix that problem before it gets released for the masses
