Re: Confused over name of eth connection (and more...)

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

> On 28 June 2017 at 17:24 Thomas Haller <thaller redhat com> wrote:
>
> Hi,
>
> On Wed, 2017-06-28 at 16:15 +0100, Colin Helliwell wrote:
>
> > The system has eth0 and a gsm connection (via ModemManager).
> > I have in /etc/network/interfaces:
> >  auto lo
> >  iface lo inet loopback
> >  auto eth0
> >  iface eth0 inet dhcp
> >
> > NetworkManager.conf is:
> >  [main]
> >  plugins=ifupdown,keyfile
> >  dns=default
> >  rc-manager=file
> >
> > [connectivity]
> >
> > [ifupdown]
> >  managed=true
> >
> > First off, up/down: from reboot
> > root@wg:~# nmcli -c no conn show
> > NAME UUID TYPE DEVI
> > CE
> > eth0 129206d8-d28f-47c7-9f9a-f9ddb1cb5218 ethernet eth0
>
> the connection profile "eth0" is in-memory-only and generated by NM. It
> does so, because it finds some pre-existing configuration on the device
> eth0, and assumes that NM should not interfere with the interface.
> Basically, NM is not really actively managing this interface.
>
> Avoid this, by not configuring the interface outside of NM, before
> starting NM. If you mention the interface in /etc/network/interface, I
> would presume that the interface is already preconfigured. Don't do
> that, if you don't want that.

Ah yes. Thanks Thomas - that is indeed the reason for my confusion. I've removed eth0 from interfaces and now 
it's making much more sense again.

...

> > # Generated by NetworkManager
> > nameserver 192.168.10.254
> > root@wg:~# nmcli conn up O2
> > PPP generic driver version 2.4.2
> > PPP BSD Compression module registered
> > PPP Deflate Compression module registered
>
> who prints these PPP messages?

Those are just console debug messages from ModemManager firing up pppd

> > Connection successfully activated (D-Bus active path:
> > /org/freedesktop/NetworkManager/ActiveConnection/2)
> > root@wg:~# cat /etc/resolv.conf
... 
> > round-trip min/avg/max = 510.785/535.474/592.168 ms
...

> I don't see it. What do you think is wrong there?

That was just another example of what I wasn't grasping before ;)