[Galene] Re: galene on IPv6 only

[Juliusz Chroboczek <jch@irif.fr>]

Hello,

> It looks like galene does not want to work on an IPv6 only server.

Thanks a lot for your testing, that's the kind of deployment that we
should be supporting.

> I also get messages related to IPv4-ish stuff.
>   Failed to enable mDNS over IPv4:
>     (listen udp4 224.0.0.0:5353: socket: protocol not supported)


mDNS is disabled by default for a very long time.  See galene.go line 49:

    flag.BoolVar(&group.UseMDNS, "mdns", false, "gather mDNS addresses")

I think the issue here is that UseMDNS is not obeyed by the relay test.
I'll fix that ASAP.

>   Relay test failed: timeout 2026/03/19 07:41:38
>     Perhaps you didn't configure a TURN server?
>   TURN: no public addresses
> 
> The second message is benign and only indicates the relayTest() test
> has failed even though it should not be run if there is no IPv4.

RelayTest is run unconditionally, since it should be successful with an
IPv6 TURN server.  The issue here is that the built-in TURN server does
not implement RFC 6156, you need to use Coturn or some other full-featured
TURN server.

We should probably run two relay tests, one over IPv4 and one over IPv6.

> This is IPv6 so no need for ICE, STUN, TURN, etc.

I, too, used to be optimistic about IPv6 ;-)

ICE is still required, since both address selection and blackhole
detection are done by ICE.  STUN and TURN are useful if there's a firewall
in the way, which sadly is often the case, even with IPv6.

> There is nothing on the local lan (its in a datacenter) so no need for
> mDNS and running mDNS is *very* bad form in that type of environment.

Yes, mDNS is disabled by default.  I need more information to understand
why it's not being disabled in your case.

> If instead of using the IPv6 address inside [] I use the host name, then
> not solved.  Even though the host has an AAAA DNS record and no
> A record, the bind does not work if the host name is specified.  This
> may be an upstream problem in the go net library.

Interesting.  I'll see if I can reproduce it.

-- Juliusz