[Pkg-utopia-maintainers] Bug#929010: Bug#929010: avahi-daemon: /etc/network/if-post-down.d/avahi-daemon is slow on eth0

[Vincent Lefevre]

On 2019-05-16 16:09:04 +0200, Vincent Lefevre wrote:
> On 2019-05-16 15:59:09 +0200, Vincent Lefevre wrote:
> > On 2019-05-16 14:41:44 +0200, Michael Biebl wrote:
> > > Am 16.05.19 um 14:22 schrieb Vincent Lefevre:
> > > > On 2019-05-16 14:15:37 +0200, Michael Biebl wrote:
> > > >> Looks like you have a local resolver configured in /etc/resolv.conf
> > > >> (which should be reachable via lo, even if eth0 is down).
> > > > 
> > > > Yes, /etc/resolv.conf contains
> > > > 
> > > > nameserver 127.0.0.1
> > > > nameserver 192.168.1.1
> > > > 
> > > > as I use "unbound".
> > > 
> > > So host talks to unbound, which apparently takes those 12s to answer.
> > > Not sure what can be done about this in avahi-daemon. Ideas?
> > 
> > Should this be regarded as a bug in unbound, then?
> 
> Actually, no, unbound is not the problem:
> 
> Whether I have
> 
> nameserver 127.0.0.1
> nameserver 192.168.1.1
> 
> or just
> 
> nameserver 192.168.1.1
> 
> in /etc/resolv.conf, "time host -t soa local." shows a 10-second
> timeout.
> 
> Or would the old /etc/resolv.conf (with 127.0.0.1) be cached somewhere
> on the system?

According to strace (see attached output), even though /etc/resolv.conf
is read, there is a connection to 127.0.0.1, though this may not be
related. But... unbound is still not the issue. The strace output shows
that it is not 127.0.0.1 (unbound) that times out, but 192.168.1.1.

And indeed, with only

nameserver 127.0.0.1

in /etc/resolv.conf, "host -t soa local." immediately gives

Host local not found: 2(SERVFAIL)

-- 
Vincent Lefèvre <vincent at vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
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