Re: Question about cgdcont --> ip, ipv4v6, ipv6 --> MM--> NM?

[Dan Williams <dcbw redhat com>]

On Tue, 2014-09-30 at 21:52 +0200, Thomas Schäfer wrote:
> Hi,
>
> I am testing a little bit ipv6 (v6 only and v4/v6-dualstack) mobile 
> connections via UMTS and LTE.
>
> While modemmamanger
>
> mmcli -m 0 --simple-connect="apn=internet,ip-type=ipv4v6"
> mmcli -m 0 --simple-connect="apn=internet,ip-type=ipv6"
>
> works. (using qmi, mbim and/or at+cgdcont ) I want to go up - to 
> networkmanager.
>
> So I am missing the possibility to configure the apn-type via NM .
>
> (gsm section)
> https://developer.gnome.org/NetworkManager/unstable/ref-settings.html
>
>
> http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/libnm-util/nm-setting-gsm.h
>
> How is it possible to set the IP-version? 

You configure the IPv4 and IPv6 methods, and optionally set "may-fail".
The logic is in
src/devices/wwan/nm-modem.c::nm_modem_get_connection_ip_type().  So, if
your modems supports IPV4V6:

ip4-method=auto, ip6-method=auto => IPV4V6
ip4-method=auto, ip6-method=ignore => IP
ip4-method=disabled, ip6-method=auto => IPV6

If the modem does not support IPV4V6, then NM will use the "may-fail"
property:

ip4-method=auto, ip6-method=auto, ip6-may-fail=yes => IP
ip4-method=auto, ip6-method=auto, ip4-may-fail=yes => IPV6

Dan