On Fri, 16 Apr 2021 23:22:30 -0400
Hendrik Boom <hendrik@???> wrote:

> On Sat, Apr 17, 2021 at 08:36:23AM +1000, Ralph Ronnquist via Dng
> wrote:
> > On Fri, 16 Apr 2021 18:24:23 -0400
> > Hendrik Boom <hendrik@???> wrote:
> >
> > > Hers's the /etc/resolv.conf on my davuan buster laptop:
> > >
> > > # Generated by Connection Manager
> > > nameserver ::1
> > > nameserver 127.0.0.1
> > >
> > > Now I have no problem resolving domain names, whither in
> > > chromium, firefox-esr, or even just ping.
> > >
> > > But a far as I know, I have never put a dns esolver on the laptop.
> > >
> > > Does devuan do this for me?
> > > Have I done it and forgotten?
> > >
> > > How should I find just how dns lookup is done on my machine,
> > > and how should it be done?
> >
> > In order to determine which process if any is listening on port 53
> > (the registered DNS port) do, as root, "netstat -lnp | grep -w 53",
> > or if you prefer less typing "ss -lnp | grep -w 53".
>

> root@midwinter:~# netstat -lnp | grep -w 53
> tcp        0      0 127.0.0.1:53            0.0.0.0:*
> LISTEN      1686/connmand tcp6       0
> 0 ::1:53                  :::*                    LISTEN
> 1686/connmand udp        0      0 127.0.0.1:53
> 0.0.0.0:*                           1686/connmand udp6       0
> 0 ::1:53                  :::*
> 1686/connmand root@midwinter:~#

>
> Looks as if the connection manager is taking over dns.
>
> Who knew? And whom does it talk to? Does it contain its own
> recursive DNS resolver? Or does it just pick up on the DHCP signals
> it gets from elsewhere and take over?
>
> Interesting.

I don't use connman myself but according to
https://wiki.archlinux.org/index.php/ConnMan#Avoiding_conflicts_with_local_DNS_server
the DNS feature can be disabled with a startup argument; possibly there
is an /etc/default/connman configuration script for that, or else a
magic hand to init script itself might work.

It doesn't directly say how the connman resolver connect "upstream" but
(following the git docs it points to) there seems to be one or more
configuration files somewhere with some "INI format" configuration
settings to declare "Nameservers" and "FallbackNameservers" for connman.

Ralph.