wireguard android don't prefer IPV6 endpoint

[Harsh Shandilya]

Hey Jérémy,

On 2021-01-02 08:27, Jérémy Prego wrote:
> I confirm the same problem in wifi
> 
> Le 27/12/2020 à 07:02, Jérémy Prego a écrit :
>> hello,
>> 
>> I've always encountered a bug with android wireguard when using an 
>> ipv4
>> / ipv6 endpoint.
>> 
>> I tested with two phones:
>> Huawei p10 lite android 8.0 emui 8
>> Xiaomi poco m3 android 10.0 miui 12
>> 
>> When i'm in LTE (not yet been able to test in wifi), wireguard 
>> connects
>> to the endpoint in ipv4 and not in ipv6, and i don't understand why it
>> is doing that.

The WireGuard Android client is designed to prefer IPv4 over IPv6 as of 
now 
(https://git.zx2c4.com/wireguard-android/tree/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java#n97). 
This may or may not change in the future, and we'll announce here if it 
does.

>> However, chrome, for example, does use ipv6 by default and not ipv4.
>> 
>> My phone does recover an ipv6 in 2a01: cb1a ........ / 64 and not an
>> ipv6 type fc00 / fd00 / fe80 ...
>> I also specify that if I only have an AAAA record, the tunnel works 
>> fine
>> in ipv6. but suddenly, I can no longer connect to wifi which only have 
>> ipv4.
>> 
>> I would like wireguard to favor ipv6 when it is available, and 
>> otherwise
>> switch to ipv4.
>> 
>> Is it possible ?
>> 
>> Thanks,
>> 
>> Jerem

Cheers,
Harsh