On Tue, Sep 8, 2026 at 9:32 AM <[email protected]> wrote:
> On Tue, Sep 08, 2026 at 11:19:36AM +0200, Vincent Lefevre wrote:
> > On 2026-09-08 08:34:37 +0100, Jonathan Dowland wrote:
> > > That sounds like faulty applications, which could or should be fixed.
> >
> > or the C library?
> >
> > > Vincent gave the example of wget, but I can't reproduce his problem;
> > > I don't _think_ wget is faulty.
> >
> > Other applications are also affected by the issue, but in different
> > and surprising ways:
>
> [...]
>
> all of them are consistent with the hypothesis that the
> application is getting both an IPv6 (AAAA record) and
> IPv4 (A) address when trying to resolve the name, and
> for some reason first try the IPv6 (and for some other
> don't fall back to IPv4 on failure).
>
Aren't applications _supposed_ to try ipv6 first and, if that doesn't work,
fall back to ipv4?
If I start wireshark and do
traceroute joooj.vinc17.net
there's a request for the A record, immediately followed by a request for
the AAAA record
I already tried the traceroute, so the answers are cached; A record
response comes back in 0.001 seconds and the AAAA response comes back in
0.000
terminal output looks like
$ traceroute joooj.vinc17.net
traceroute to joooj.vinc17.net (2001:4b99:1:3:216:3eff:fe20:ac98), 30 hops
max, 80 byte packets
1 2600:4040:<.. etc ..>
. . .
12 joooj.vinc17.net (2001:4b99:1:3:216:3eff:fe20:ac98) 85.097 ms 84.899
ms 85.011 ms
Regards
Lee
