Signal desktop app does not work in IPv6-only environment.

[mdavids]

#2327 still seems an open issue.

I have an IPv6-only system (with IPv4 disabled on my interface) and a NAT64/DNS64 setup to reach the IPv4-world. I can see the Signal desktop app is attempting A and AAAA queries for 'textsecure-service.whispersystems.org' (among other things, like 'cdn.signal.org' and 'updates2.signal.org') and then trying to prefer the A-record over the AAAA record, even though there is no IPv4-connectivity possible. This obviously fails. The AAAA answer is not used.

When I reconfigure my DNS64 resolver in such a way that an A-query gives a NODATA result, so that AAAA is the only reply returned, everything works. However, I can only do that in my own environment, not in other similar IPv6-only environments, maintained by others.

It seems to me that Signal (or Electron, or NodeJS for that matter) has no, or a dysfunctional 'Happy Eyeballs'-implementation. Could be NodeJS: nodejs/node#6307

Is this something that can be fixed?

[kenpowers-signal]

I can see a PR for node referenced in that issue: nodejs/node#31567

Once a fix reaches Node and then eventually Electron this issue should work itself out after we update to that version of Electron. I don't think there's much else we can do on our end though.

[huaracheguarache]

Looks like the IPv6 fix has been merged: nodejs/node#39987

And a new version with the fix is on the way: nodejs/node#40119

[indutny-signal]

We should get with an Electron update eventually. Great stuff!

[treysis]

It's more or less a NodeJS thing that is solved in v17. Although still no happy eyeballs. However, electron will only support that after the NodeJS fix makes it into v18 (LTS) and electron switching over to v18, and then Signal switching to the latest electron release after that. I don't expect that to happen well into 2022, maybe even 2023.

NodeJS generally gives the option to override the reordering of DNS results in favor of IPv4. Not sure if electron has the option to pass this on. In that case it could be 'fixed' by Signal itself. There's also some option in the latest NodeJS v16.x release to override the DNS reordering. Don't remember if this can ne set by a config file or only via cmdline (aside from passing the option in code after importing the module).

[optimismus]

This seems to be still open/unfixed. Signal App works great, Signal Desktop doesn't work. As far as I could see chat.signal.org which is used by Signal Desktop is IPv4-only:

Name:    chat.signal.org
Addresses:  76.223.92.165
          13.248.212.111

while Signal App uses update2.signal.org, which has dualstack:

Name:    updates2.signal.org.cdn.cloudflare.net
Addresses:  2606:4700:4400::ac40:91e4
          2606:4700:4400::6812:2a1c
          172.64.145.228
          104.18.42.28
Aliases:  updates2.signal.org

Is it still a software problem?

Regards
Axel

[kubrickfr]

This has some real-life implications. I went to a google office recently, and their guest network is IPv6 only (with NAT64 and DNS64), and it's impossible to use signal-desktop from there...

[KemalSoysal]

I have the same issue, is any help needed for resolving this issue?

[pavel-odintsov]

Hello!

I just finished deployment of IPv6 only network for my home office and noticed that Signal Desktop on Linux is not working well with NAT64 and native IPv6. Majority of apps work fine and it's clearly blocker for migration to IPv6.

Many engineers use Signal and ability to use it in IPv6 only environment is crucial for migration of Internet to IPv6 in coming decades.

Any chance to get more attention to this issue? Can I help in any way?

It's not actually very clear why it fails as I can see IPv6 addresses for signal.org and site itself works fine for me.

Thank you!

[treysis]

Electron framework still uses old NodeJS version which always prefers IPv4.