MC7304 + Get current settings + manual IP settings

[Bjørn Mork]

Aleksander Morgado <aleksander at aleksander.es> writes:
> On Sun, Jun 5, 2016 at 6:33 PM, Aleksander Morgado
> <aleksander at aleksander.es> wrote:
>> I've been playing today with --wds-get-current-settings, trying to
>> manually setup the WWAN without using DHCP, and failed miserably, not
>> sure why.
>>
>> Once I get the device in 802-3 LLP, connected via WDS Start Network,
>> and then get the current settings, I basically just do:
>>
>> $ sudo ip link set dev wwan1 up
>> $ sudo ip -4 addr add 47.59.92.71/255.255.255.240 dev wwan1
>> $ sudo ip link set dev mtu 1430
>> $ sudo ip route add default via 47.59.92.65 dev wwan1
>>
>> And try to ping...
>> $ ping -I wwan1 8.8.8.8
>>
>> It won't work at all.
>>
>> But, if I just run dhclient on the interface, which ends up setting
>> the same setup, it ends up working...
>>
>> $ dhclient wwan1
>>
>> $ ping -I wwan1 8.8.8.8
>> PING 8.8.8.8 (8.8.8.8): 56 data bytes
>> 64 bytes from 8.8.8.8: seq=0 ttl=52 time=1808.345 ms
>> 64 bytes from 8.8.8.8: seq=1 ttl=52 time=809.933 ms
>> 64 bytes from 8.8.8.8: seq=2 ttl=52 time=68.077 ms
>>
>> Interestingly, if I explicit tell ModemManager to request static IP
>> settings to NetworkManager, I do get connected (I assume without DHCP
>> involved).
>>
>> Any idea? What am I missing? Why does DHCP actually work here and not
>> manual IP settings?
>
> I just found this old thread where Dan says that "there are other
> reports of static not working with Sierra Qualcomm-based 73xx devices
> too."
> https://lists.freedesktop.org/archives/modemmanager-devel/2014-August/001472.html
>
> Hum... Did we ever know why this is like this?

Not that I can remember.  I seem to recall similar issues with the
Huwaei E392 a long time ago.  My guess is that the firmware initializes
"something" based on the DHCP request. Host MAC address is one
possibility.  We don't care if the address is wrong, but Sierra could
have improved the firmware by making it refuse to send any packets
before the host MAC is known. Another wild guess...

How about if you use the modem in raw-ip mode?  Does it work with manual
IP config then?

Yes, I should bring out the EM7305 and test myself, but the weather is
nice and the bike is working... ;)


Bjørn