GNU bug report logs - #55335
openssh-service no longer listens on IPv6

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From: Jack Hill <jackhill <at> jackhill.us>
To: Ludovic Courtès <ludo <at> gnu.org>
Cc: Christopher Baines <mail <at> cbaines.net>, 55335 <at> debbugs.gnu.org
Subject: bug#55335: openssh-service no longer listens on IPv6
Date: Sat, 14 May 2022 15:09:55 -0400 (EDT)

[Message part 1 (text/plain, inline)]

On Sat, 14 May 2022, Ludovic Courtès wrote:

> Hi,
>
> Thinking about it, what do you think is the risk of using AF_INET6
> unconditionally?
>
> AFAICS it just works.  Is there a switch somewhere that might affect
> that behavior?

Yes, I beleive that it's in sysctl:

```
$ sysctl net.ipv6.bindv6only
net.ipv6.bindv6only = 0
```

If enabled, the v6 socket wouldn't work for v4. Disabled is the default on 
Guix System. I don't know what would happen if v6 were disabled entirely. 
Hopefully that's not something we have to worry about in 2022.

HTH,
Jack

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