Hello Alex,   
      
   On Tuesday January 23 2018 02:09, you wrote to me:   
      
    MvdV>> Thanks, The odd thing is that I can connect to my web server   
    MvdV>> locally via IPv6, but the connection via IPv4 seems to be the   
    MvdV>> prefered one. To connect via IPv6 I must force an IP6   
    MvdV>> connection by using a host name without an IPv4 address. Maybe   
    MvdV>> the relay introduces a delay that makes IPv4 preferent on the   
    MvdV>> otherwise fast local connection?   
      
    AS> No, it's the default "prefer IPv4 over IPv6" in your system or browser   
    AS> settings.   
      
   Odd. Because this only happens when I use the RELAY6 method when locally   
   accessing my website. When I used the netsh method, I always connected via   
   IPv6. And wneh connected other websites aroud the world, IPv6 is the preferred   
   method.   
      
    AS> For Firefox based browsers, check the following about:config settings:   
      
    AS> network.dns.disableIPv6 = false   
      
   Check   
      
    AS> network.http.fast-fallback-to-IPv4 = false (Pale Moon with works for   
    AS> me with true though)   
      
   Set to true here...   
      
    AS> In case of WinXP, it's forced default behavior of "prefer IPv4" and   
    AS> there is a way to fix it by modifying netsh prefixpolicy as shown   
    AS> here: https://sites.google.com/site/jrey42/Home/ipv6/prefixpolicies   
      
   Hmmm...   
      
   D:>netsh   
   netsh>prefixpolicy   
   Der folgende Befehl wurde nicht gefunden: prefixpolicy.   
   netsh>   
      
    AS>>> ipv6.dynamic.ziggo.nl [2001:1c02:1100:d700:f1d0:2:280:5555]   
    AS>>> but your ISP does not seem to assign proper reverse DNS for   
    AS>>> customers.   
    MvdV>> Indeed, that is a bit of a joke. Every IPv6 addres   
    MvdV>> (2001:1c02::/32) of my provider backresolves to   
    MvdV>> ipv6.dynamic.ziggo.nl.   
      
    AS> Is it dynamic or static?   
      
   Dynamic.   
      
    AS> And if it's static, why your ISP can't  provide a proper backresolve   
    AS> by customer request?   
      
   I don't know. They do not seem to know themselves either...   
      
   Cheers, Michiel   
      
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    * Origin: he.net certified sage (2:280/5555)