Re: Getting (a little more) started

[Colin Helliwell <colin helliwell ln-systems com>]

> On 07 April 2017 at 17:35 Dan Williams <dcbw redhat com> wrote:
>
> On Fri, 2017-04-07 at 17:17 +0100, Colin Helliwell wrote:
>
> > > On 07 April 2017 at 17:15 Colin Helliwell <colin.helliwell@ln-syste ms.com> wrote:
> > >
> > > > On 07 April 2017 at 17:06 Dan Williams <dcbw redhat com> wrote:
> > > >
> > > > On Fri, 2017-04-07 at 16:12 +0100, Colin Helliwell wrote:
> > > >
> > > > > I've got NM installed n running on my embedded system. I can
> > > > > 'nmcli
> > > > > conn up modem' and the ppp link on my GSM modem comes up nicely
> > > > > -
> > > > > ifconfig reports inet and P-t-P addresses, and I seem able to
> > > > > ping/traceroute through it to the interweb, but I may have some
> > > > > clutter.
> > > > >
> > > > > Being embedded and headless I don't have nice GUI widgets to
> > > > > help me,
> > > > > so I might need some more manual configuration or tidying of
> > > > > stuff.
> > > > > I'm using systemd, and also have running /lib/systemd/systemd-
> > > > > networkd, /lib/systemd/systemd-resolved, /usr/bin/dnsmasq,
> > > > > /sbin/dhclient.
> > > > > I built NM with '--with-resolvconf=yes', and the [Yocto] image
> > > > > also
> > > > > has the resolveconf package included, but I'm unclear how these
> > > > > relate to "/lib/systemd/systemd-resolved" and whether they have
> > > > > common/conflicting configurations.
> > > >
> > > > They will potentially conflict as there can only be one manager
> > > > of
> > > > /etc/resolv.conf, and both these things want to manage it.
> > > >
> > > > NM 1.6+ has support for systemd-resolved and this will
> > > > automatically be
> > > > used if resolv.conf is managed by systemd-resolved and no other
> > > > mode is
> > > > configured in NetworkManager.conf.
> > >
> > > Thanks.
> > > So leave out the resolvconf package and leave it to NM & systemd-
> > > resolved?
> >
> > And if so, is '--with-resolvconf=yes' aimed at resolvconf (i.e. set
> > it to no instead), or at systemd-resolved...?
>
> Even if you set it to yes, you should still be able to set the
> resolv.conf management mode via NM.conf. The options are "dns" and
> "rc-manager"; in your case if you want to use systemd-resolved as the
> main management mode you'd:
>
> dns=systemd-resolved
> rc-manager=symlink
>
> I think.

Thanks. I've tidied up a bit and removed resolveconf (the app) and dnsmasq. Still seems to work, with or 
without those settings, but I'm not sure what - if anything - I should be seeing in the various versions of 
resolv.conf
Shouldn't the above settings cause /etc/resolv.conf [symlink'd here to /run/systemd/resolve/resolv.conf] to 
have the active nameserver(s) added?
There's a IP4.DNS[1] for in 'nmcli dev show', but I thought I'd read that some apps/libs rely on 
/etc/resolv.conf?
However, when I bring up the GSM modem connection, /etc/resolv.conf *is* then modified to have the Eth0 dns 
server.