Dual stack connection on EM7430

[Aleksander Morgado]

On Wed, Apr 12, 2017 at 9:14 PM, Dan Williams <dcbw at redhat.com> wrote:
>> Have tried both the options but i still get the policy mismatch error
>> when
>> i try to activate for ip-type=6, even the profiles support both IPV4
>> and
>> IPV6, it allows to create a network either one of them.
>>
>> It should be like this right, if we don't specify the ip-type option
>> as
>> part of start-network should be able to transmit message using both
>> IPV4
>> and IPV6.
>
> Last I checked with Verizon (over a year ago), specifically with
> VZWINTERNET on an MC7750 and UML290, the behavior that you are doing
> was how the Verizon Broadband Access Manager (VZAM) operated to acquire
> an IPv4 and IPv6 address.  And yes, the modem had VZWINTERNET with a
> V4V6 PDP context as shown by CGDCONT.
>
> 1) create a WDS client
> 2) call StartNetwork with ip-type=v4
> 3) get current settings with client from #1
> 4) create a new WDS client
> 5) call StartNetwork with ip-type=v6
> 6) get current settings with client from #4
>
> Both v4 and v6 addresses get configured on the same network interface,
> but are acquired through different WDS clients and StartNetwork
> requests.  As far as I know, QMI has no "v4v6" ip-type attribute for
> StartNetwork.
>
> Perhaps that's changed, would be nice to verify what VZAM or other QMI-
> based Windows connection managers are doing these days to get a dual-
> stack connection.

In ModemManager the flow is a bit different to request this same
setup. Instead of calling StartNetwork with a given "IP Family
Preference" TLV (as you would have with
--wds-start-network="ip-type=X"), we instead call the "WDS Set IP
Family" command before calling "WDS Start Network" and if that
succeeds, we won't add the TLV. Only if the "WDS Set IP Family"
command fails, we do set the TLV.

We could test this approach if we had a --wds-set-ip-family command in
qmicli, but we don't yet; patches welcome :)

-- 
Aleksander
https://aleksander.es