Modem not connecting on Ubuntu 16.04 (whereas it did on Ubuntu 14.04)

[Ajay Garg]

Thanks Aleksander, for your (as always) detailed and crisp analysis.


On Tue, Aug 30, 2016 at 8:09 PM, Aleksander Morgado
<aleksander at aleksander.es> wrote:
> On Tue, Aug 30, 2016 at 8:56 AM, Ajay Garg <ajaygargnsit at gmail.com> wrote:
>> The reason turned out that I had disable USB-3.0 support in BIOS.
>> When I turned it on, the modem started connecting in both 14.04 and 16.04.
>>
>> However, in 14.04 the "wwan" interface appears fine (and after running
>> "dhclient" on it, the internet works fine).
>> However on 16.04, no "wwan" interface appears, even after mmcli -m 11
>> --simple-connect="apn=airtelgprs.com" has resulted in successful-connection.
>>
>>
>> A maybe related symptom is that ethernet-interfaces appear as "eth0" and
>> "eth1" in 14.04, but as "enp1s0" and "enp2s0" in 16.04. But even then, NO
>> ADDITIONAL INTERFACE appears when mmcli -m 11
>> --simple-connect="apn=airtelgprs.com" has resulted in successful-connection
>> on 16.04.
>>
>> Looks very weird; I will be thankful for any help.
>
> --simple-connect doesn't make interfaces appear/disappear :) The WWAN
> interface should be detected and available before you even attempt to
> run --simple-connect.


:O :O :O

Hasn't happened for me on Ubuntu 14.04.2 / 14.04.3 so far, not even
once in the last 1 month or so I have been working on this. However,
things have been working fine via the commands I shared in my
originating email.

The interface occurs if and only if the --simple-connect runs to
completion, successfully.

Should I be worried?

>
> Looks like you have now the "predictable network interface names"
> support in Ubuntu 16.04, coming from systemd:
> https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
>
> This means that you won't have a "wwan0" interface any more; look for
> something like "ww...."
>
> Anyway, the correct flow is to avoid manually looking for the network
> interface name. Once you have run "--simple-connect", you'll have a
> connected "bearer" object reported in ModemManager. The bearer object
> will tell you, in its details, what interface name you should use and
> also the specific connection method you're supposed to use (dhcp,
> static, ppp).

Thanks for this info Aleksander, I will keep this in mind if I do have
to take the trouble of evaluating a new version :)


>
> --
> Aleksander
> https://aleksander.es


Thanks and Regards,
Ajay



-- 
Regards,
Ajay