Setup MC7455 connection to internet with modem manager

[Dan Williams]

On Thu, 2017-06-15 at 10:52 +0200, Nassim Dahmani wrote:
> NetworkManager[1949]: <debug> [1497516042.3228]
> device[0x564bf34fc610]
> (cdc-wdm1): unmanaged: flags set to
> [user-settings,!sleeping,!loopback,!platform-
> init=0x40/0x59/unmanaged/unrealized,
> set-managed [sleeping=0x1])

The modem has been unmanaged by the configuration, it seems.  Could be
an NM bug, could be a config bug.  I'll let Thomas Haller debug
further.

But to confirm, before you run "sudo nmcli con up modem", can you run:

nmcli dev show cdc-wdm1

and we'll reconfirm that it's really "unmanaged".

Dan