ANSWERED Getting devices to prefer IPv6 on other OS.

[Abstain9194 0]

airvpn uses a /128 ULA for each interface config, which is great that IPv6 is supported, but the interface having a ULA means that devices will prefer the IPv4 more often that not. While I am aware that there are reasons to have chosen the ULA such as for privacy and having it not be routable or advertisable, this means that most airvpn servers, having poor IPv4 reputation get captcha'd to hell. Is there anyway to configure devices on Mac/Windows to prefer ULA over v4 like that of gai.conf?

[Abstain9194 0]

I am aware that there is a thread on this already but I do not have permissions to view it

[Staff 10014]

@Abstain9194

Hello!

We see the issue on that topic which is no more accessible by normal users, we must check with the web site maintainers, maybe there's a logic reason for this choice or maybe it's an error. In the meantime, if you run specific browsers on Mac and Windows here's the message posted by @OpenSourcerer as a solution at the time (August 2019, and limited to the mentioned browsers):
 

 

Quote

 

After a bit of tinkering I finally get 19/20 on ipv6-test.com running Waterfox 56.2.6 on Debian. I also get 19/20 on Chromium 70 and Firefox ESR (60.4.0). Waterfox addons also indicate that the browser connects to IPv6 addresses all the time. It doesn't seem to be an issue with getaddrinfo() or its config in gai.conf at all as mine is the same as Mr. kaymio's.

 

So, what did I do? I am not entirely sure, to be honest. I disconnected from AirVPN and went on doing experiments on my ISP line with native IPv6. I set

network.http.fast-fallback-to-IPv4;false
network.notify.IPv6;false

and restarted the browser. Then I reenabled the notify setting and restarted again. After that, Firefox/Waterfox magically started to prefer IPv6 and ipv6-test.com gave me 17/20. This is due to my router blocking ICMP (Fritz!Box calls this "Stealth Mode" ) so it should be 19/20 if I decide to stop filtering it.

 

I reconnected to AirVPN and voilà, still prefers IPv6, now 19/20.

 

Kind regards
 

[OpenSourcerer 1441]

10 minutes ago, Staff said:

We see the issue on that topic which is no more accessible by normal users, we must check with the web site maintainers, maybe there's a logic reason for this choice or maybe it's an error.

There was some form of discussion at the end there which turned a bit toxic, if I remember correctly.
 

3 hours ago, Abstain9194 said:

Is there anyway to configure devices on Mac/Windows to prefer ULA over v4 like that of gai.conf?

netsh interface ipv6 show prefixpolicies looks very similar.

[Abstain9194 0]

It doesn't seem that this browser setting with getting firefox to remember the previous preferences etc... works on my side at least, and seems a bit hacky. Also it doesn't seem that ipv6-test.com is great for this either since it detects v6 defaults despite v6 almost never being the version used for v6 enabled sites. The reason I noticed this was with proton using it's GUA address for wireguard v6 rather than a ULA and that I was almost always on v6 (according to ipvfoo extension) when using it. I could try adding an extra dummy interface GUA ip to the config and test this maybe. I also didn't have access to the entire message when the usage of ULA was justified so I supposed switching to GUA is not an option.

[OpenSourcerer 1441]

27 minutes ago, Abstain9194 said:

Also it doesn't seem that ipv6-test.com is great for this either since it detects v6 defaults despite v6 almost never being the version used for v6 enabled sites

Aah, please don't use ipv6-test.com anymore, it's been severely undermaintained for at least two years now. The v6 tests work maybe 10% of all times, and even the v4 tests are very slow to show. Kind of a bane to quote a post from five years ago; I wasn't even sure those Firefox options were still in effect but at least they still are. Day by day it seems nothing is changing but look back and everything is different.

[Staff 10014]

22 minutes ago, OpenSourcerer said:

Kind of a bane to quote a post from five years ago; I wasn't even sure those Firefox options were still in effect

Hello!

Yes, that's probably why it is no more available. It was a FAQ and then removed as outdated. @Abstain9194 please ignore the out of date recommendation.

Kind regards
 

[Abstain9194 0]

It's preliminary but it appears that I've missed out on a very obvious config on firefox being network.dns.preferIPv6. Not sure if this only works with DOH as now but it seems to be working even with a ULA interface IP

[OpenSourcerer 1441]

On 11/10/2024 at 1:00 PM, Abstain9194 said:

It's preliminary but it appears that I've missed out on a very obvious config on firefox being network.dns.preferIPv6. Not sure if this only works with DOH as now but it seems to be working even with a ULA interface IP

I seem to remember this setting only prioritizing DNS resolution over an IPv6 DNS server. It's interesting that I cannot find any documentation about this anymore..

[Abstain9194 0]

4 hours ago, OpenSourcerer said:

I seem to remember this setting only prioritizing DNS resolution over an IPv6 DNS server. It's interesting that I cannot find any documentation about this anymore..

This setting does see to preferentially get AAAA and go to v6 addresses of sites, it's a shame this option isn't on my default or easily accessible, v6 is very important.

[OpenSourcerer 1441]

On 11/12/2024 at 2:12 AM, Abstain9194 said:

it's a shame this option isn't on my default or easily accessible, v6 is very important.

Know that for most people it's not default to be connected to a VPN. Or to a network assigning v6 ULAs.