Dear Janne,   
      
   25 Oct 18 16:04, you wrote to you:   
      
    JJ> On 2018-10-25 09:06, Janne Johansson : Benny Pedersen wrote:   
    >> On 2018-10-25 00:40, Benny Pedersen : Michiel van der Vlist wrote:   
    >>>  MvdV> and up).  If the destination address is a 6to4 tunnel   
    >>> address   
    >>>  MvdV> (2002::/16) many OSs default to IPv4 if an IPv4 address is   
    >>> present.   
    >>>   
    >>> time to update to a later glibc where ipv6 is prefered over ipv4   
    >>> failback   
    >>   
    >> I think its mostly a setting in your resolv.conf or similar file to   
    >> change default priority of v4 or v6 and not so much a age-of-glibc   
    >> issue.   
      
    JJ> Also, at least OpenBSD (if we are still at 'Many OSes') defaults to   
    JJ> prefer v4, with a resolv.conf option:   
    JJ> family inet6 inet4   
    JJ> to flip it around if you want it the other way around.   
      
   For FreeBSD, it's in /etc/rc.conf   
      
   ip6addrctl_enable="YES"   
   ip6addrctl_policy="ipv6_prefer"   
      
   and /etc/ip6addrctl.conf for fine-tuning the address selection policy:   
      
   root@vas:~ # ip6addrctl show   
   Prefix                          Prec Label      Use   
   ::1/128                           50     0    14494   
   ::/0                              40     1   491602   
   ::ffff:0.0.0.0/96                 35     4        0   
   2002::/16                         30     2        0   
   2001::/32                          5     5        0   
   fc00::/7                           3    13        0   
   ::/96                              1     3        0   
   fec0::/10                          1    11        0   
   3ffe::/16                          1    12        0   
   root@vas:~ #   
      
      
      
      
   Victor Sudakov, VAS4-RIPE, VAS47-RIPN   
   --- GoldED+/BSD 1.1.5-b20160322-b20160322   
    * Origin: Ulthar (2:5005/49)