MC7430 Connection problem

[Alexandru Ardelean]

On Mon, Oct 2, 2017 at 7:36 PM, Aleksander Morgado
<aleksander at aleksander.es> wrote:
>>> However when I try to connect with the modem to the LTE network it looks as
>>> if the modem is successfully attached to the cell but I don't get an IP
>>> address on any of my interfaces wwan0 or wwan1.
>>>
>>> When i run the qmi-network tool I get the following output
>>>
>>> sudo qmi-network /dev/cdc-wdm0 start
>>> Loading profile at /etc/qmi-network.conf...
>>>     APN: internet
>>>     APN user: unset
>>>     APN password: unset
>>>     qmi-proxy: no
>>> Checking data format with 'qmicli -d /dev/cdc-wdm0 --wda-get-data-format
>>> '...
>>> Device link layer protocol retrieved: raw-ip
>>> Getting expected data format with 'qmicli -d /dev/cdc-wdm0
>>> --get-expected-data-format'...
>>> Expected link layer protocol retrieved: 802-3
>>> Updating kernel link layer protocol with 'qmicli -d /dev/cdc-wdm0
>>> --set-expected-data-format=raw-ip'...
>>> error: cannot set expected data format: Expected data format not updated
>>> properly to 'raw-ip': got '802-3' instead
>>
>> This is weird.
>> AFAIK, 802-3 does not work on MC7430 ; just raw-ip.
>>
>
> There are 2 things we do here in the qmi-network script (same thing is
> done in ModemManager):
>   * the first one is asking the modem which is the link layer protocol
> it expects, and in this case the modem is telling us it expects
> "raw-ip" (MC74xx only support raw-ip)
>   * the second one is asking the kernel which is the link layer
> protocol it expects, and in this case the kernel is telling us it
> expects "802.3" (the default one).
>
> So, we try to tell the kernel it should use raw-ip and that fails.
> Which kernel version are you using? The Linux kernel must be >= 4.5
> for the raw-ip support to work!

So, from the report, it seems the kernel is 4.9.52, which should have
the raw-ip support.
That's why it seemed weird to me.

>
>>> Starting network with 'qmicli -d /dev/cdc-wdm0
>>> --wds-start-network=apn='internet'  --client-no-release-cid '...
>>
>> Maybe add
>> --wds-start-network=apn='internet',ip-type=4,autoconnect=yes
>> here.
>>
>> And maybe try a
>> --wds-stop-network=disable-autoconnect
>> before the --wds-start-network.
>>
>
> No, don't think autoconnect has anything to do with this.

In my case, I prefer
--wds-stop-network=disable-autoconnect
vs
--wds-stop-network=0xffffffff

But now that I think about it, this is not needed here.

>
>>
>>> Saving state at /tmp/qmi-network-state-cdc-wdm0... (CID: 35)
>>> Saving state at /tmp/qmi-network-state-cdc-wdm0... (PDH: 63159616)
>>> Network started successfully
>>>
>>> If I then try to obtain an ip address I get nothing
>>>
>>> sudo dhclient -v wwan0
>>> Internet Systems Consortium DHCP Client 4.3.1
>>> Copyright 2004-2014 Internet Systems Consortium.
>>> All rights reserved.
>>> For info, please visit https://www.isc.org/software/dhcp/
>>>
>>> Listening on LPF/wwan0/3a:0b:18:73:f4:e1
>>> Sending on   LPF/wwan0/3a:0b:18:73:f4:e1
>>> Sending on   Socket/fallback
>>> DHCPDISCOVER on wwan0 to 255.255.255.255 port 67 interval 8
>>> DHCPDISCOVER on wwan0 to 255.255.255.255 port 67 interval 8
>>> DHCPDISCOVER on wwan0 to 255.255.255.255 port 67 interval 15
>>> DHCPDISCOVER on wwan0 to 255.255.255.255 port 67 interval 14
>>> DHCPDISCOVER on wwan0 to 255.255.255.255 port 67 interval 16
>>> No DHCPOFFERS received.
>>> No working leases in persistent database - sleeping.
>>>
>>>
>>> Any ideas what might be the issue ?
>
> The modem expects raw-ip, and the kernel is expecting 802.3. That's one issue.
>
> The other issue is that dhclient doesn't support interfaces configured
> in raw-ip mode (but you'll get there once the kernel matching to
> raw-ip happens). You can avoid using DHCP and instead retrieve static
> IP settings with --wds-get-current-settings and apply them manually
> (ip addr add XXX...) to the network interface.
>
> --
> Aleksander
> https://aleksander.es