Mobile IPv6

Device support

As the modem establishes an IP(v4) PDP context with the network, to do IPv6 the modem would need to support it (or use a full PPP context).

Devices which do/don't support an IPv6 PDP type (there are AT commands to query the modem's capabilities):

Nokia E51 (IPv4/IPv6)

ATI
Nokia

AT+GCAP
+GCAP: +CGSM,+DS,+W

AT+CGDCONT=?
+CGDCONT: (1-2),"IP",,,(0),(0)
+CGDCONT: (1-2),"IPV6",,,(0),(0)

Huawei E220 (IPv4/PPP)

ATI
Revision: 11.110.01.03.00
+GCAP: +CGSM,+FCLASS,+DS

AT+CGDCONT=?
+CGDCONT: (1-16),"IP",,,(0-1),(0-1)
+CGDCONT: (1-16),"PPP",,,(0-1),(0-1)

Vodafone (Huawei) K4505 (IPv4/PPP)

ATI
Manufacturer: Vodafone (Huawei)
Model: K4505
Revision: 11.828.03.00.11
IMEI: 354661xxxxxxxxx
+GCAP: +CGSM,+DS,+ES

AT+CGDCONT=?
+CGDCONT: (1-16),"IP",,,(0-2),(0-3)
+CGDCONT: (1-16),"PPP",,,(0-2),(0-3)

ZTE MF627 (IPv4/IPv6/PPP)

ATI
Manufacturer: ZTE INCORPORATED
Model: MF626
Revision: BD_P673M3V1.0.1B02
IMEI: 35806602xxxxxxx
+GCAP: +CGSM,+DS,+ES

AT+CGDCONT=?
+CGDCONT: (1-16),"IP",,,(0-2),(0-3)
+CGDCONT: (1-16),"PPP",,,(0-2),(0-3)
+CGDCONT: (1-16),"IPV6",,,(0-2),(0-3)

Network support

I (met) have tried connecting with a K4505 and an A&A L2TP-handover SIM using a PPP context, but it doesn't work. An IP context gives you a CONNECT response immediately, with a PPP context it sits there for a couple of seconds before returning NO CARRIER.

I see the same results with a Vodafone contract data SIM.