IPv6 with simple-connect

[Bjørn Mork]

Aleksander Morgado <aleksander at lanedo.com> writes:

> On 05/09/13 09:52, Martin Anderseck wrote:
>> I'm using the Sierra Wireless MC7710 module with IPv4 and IPv6. When I 
>> want to setup an IPv4 connection I use
>> mmcli -m 0 --simple-connect="apn=myIPv4APN,ip-type=ipv4"
>> and it works fine.
>> However if I want to setup an IPv6 connection I'd normally use
>> mmcli -m 0 --simple-connect="apn=myIPv6APN,ip-type=ipv6"
>> This always leads to 
>> error: couldn't connect the modem: 
>> 'GDBus.Error:org.freedesktop.libqmi.Error.Protocol.CallFailed: QMI 
>> protocol error (14): 'CallFailed''
>> 
>> If I have set the PDP context before using the AT commands
>> at+cgdcont=1,"IPV6","myIPv6APN"
>> then it works. This step is not necessary for IPv4 connections. 
>> 
>> If I have deleted all PDP contexts before starting the simple-connect 
>> command a new very general IPv4 entry is generated in both cases:
>> +CGDCONT: 1,"IP","","0.0.0.0",0,0
>> 
>> Is this a bug in ModemManager or do you think it's a firmware issue?
>
> The QMI implementation performs several steps to setup the IP type to
> use. Could you share a debug log of MM while trying to establish a IPv6
> connection?
>
> Bjorn and/or Dan may know more on this, as I haven't played much with
> IPv6 myself.

Nor have I, I'm afraid.  My IPv6 enabled SIM stopped working a long time
ago and I haven't bothered nagging anyone about it.  But I dug up the
commands I were using when I had it working, and compared them to what
you do in libqmi + MM now.  Looks very similar to me. But then again you
probably got the (barely tested) procedure from me in the first place...

It's very likely that I never tested the case where there was no
predefined context.  Hmm, looking at this now, there does not seem to be
anything choosing between a IPV6 or IPV4V6 PDP type unless you have a
matching predefined context. And we do really need to choose one of
those, don't we?  But the PDP type isn't part of the "start network"
command, is it?  Just indirectly by reference to a profile.  So maybe we
need to look through QMI_WDS_GET_PROFILE_LIST, possibly using
QMI_WDS_CREATE_PROFILE to make sure there is a profile with the
appropriate PDP type?

Having debug logs would most certainly be useful.  It would at least
tell us that MM goes through the expected "set ip family preference"
etc.



Bjørn