[v6ops] DHCPv6 Prefix Delegation (DHCPv6 PD) on cellular links - works ok

[Alexandre Petrescu <[e-mail]>]

v6opsers,

We succeeded in making DHCPv6 PD work natively on a cellular link.
I would claim it to be a first[*].
Packet dump available upon request.

The UE device is a Huawei E392u-12 USB dongle produced in 2011.  It 
hosts a baseband processor Qualcomm model MDM9600 (or model MDM9200, or 
an Intel - not sure).  It lets all standard DHCPv6 messaging through. 
The DHCPv6 client 'odhcpv6' is running on linux laptop.

The mobile operator's PGW assigns a /56 and sets proper forwarding for 
it.  The PGW runs on a big Cisco platform.

After the successful DHCP exchange the laptop is able to ping google 
with a src address which is manually derived out of the /56 delegated 
prefix.

That said,

DHCPv6-PD on cellular links is relevant for a few RFCs and Internet 
Drafts.  They should be improved because at places these documents are a 
little bit wrong.

DHCPv6-PD is blocked on other baseband processors, including Qualcomm 
and Balong versions; they are hosted by many smartphones, USB cellular 
dongles, mobile personal WiFi hotspots and IoT devices.  A sample list 
is available upon request.

Last but not least,

[*] earlier DHCPv6 PD on cellular links was shown on tunnel virtual 
interfaces, like VPN.

Alex