Re: Which takes priority, ipv4, or ipv6?
Vincent Lefevre <vincent@vinc17.net> writes:
> On 2023-03-27 12:48:13 +0100, Richmond wrote:
>> I have configured an ipv6 tunnel. If I visit this site:
>>
>> http://ip6.me/
>>
>> The "normal" test shows my ipv4 address, and the:
>>
>> http://ip6only.me/
>>
>> shows the ipv6 address.
>>
>> However if I switch my DNS from opendns to the one provided by my ISP
>> and then run the "normal" test it shows the ipv6.
>>
>> The note says:
>>
>> (preference depends on your OS/client)
>>
>> So how is the preference determined? It seems to be determined by the
>> DNS, but why or how do I tell for example with host -v?
>
> It appears to be random (based on past tests).
>
> But one can set the preference via "/etc/gai.conf". In particular:
>
> # For sites which prefer IPv4 connections change the last line to
> #
> #precedence ::ffff:0:0/96 100
>
> I had to uncomment this line in the past when I had IPv6 issues.
I uncommented the table and changed the 2002 to 2001 and that seems to
have prioritized ipv6 but it's a bit of guesswork for me:
precedence ::1/128 50
precedence ::/0 40
precedence 2001::/16 30
precedence ::/96 20
precedence ::ffff:0:0/96 10
Now if I go to google.com for example, ipvfoo (extension for chromium)
tells me I am using ipv6.
Reply to: