Add config to prefer IPV6 Address than IPV4
Since IPV4 address is limited in numbers and there is a migration to IPV6 could be nice you remove limitation while config IPV44Only and IPV6Only; IPV6ONly seems not working since we got a message about free ipv4 :) ... no exact denied use of IPV4 .. but make sure others use IPV6 to reach IPV4 since behind NAT.