Still struggling with this. Would appreciate any hints. Anyone tried IPv6 on a mobile connection with a shorter prefix than /64? How do you do that?
Assuming DHCPv6-PD, one basic problem is the selection of source and destination addresses for the solicit. I really don't understand how this is intended to work given any real world USB/PCIe 4G/5G modem, which basically always is a closed firmware router with one USB/PCIe interface and one radio interface. Are we supposed to have special device specific firmware support, so that we can use a magic firmware command to send solicits from a link local address to the link local ff02::1:2 multicast group over the mobile link? If so, any tips regarding actual implementations? Ruling out special modem firmware, am I right assuming that using ff05::1:3 with a GUA source from the dual-stack PDP context assigned /64 should work? And if it does, would it be OK if the solicit is wrapped in a DHCPv6 relay message? That's the most generic solution I can come up with. But maybe it's just my lack of imagination... Google finds a number of documents with lots of hand-waiving and no specifics wrt the IP addresses involved or the actual DHCPv6 packet contents. Making it look like the UE can just send a DHCPv6-PD solicit like it was an ordinary ethernet client. But I don't know of any modem where we have that kind of access to the actual tunnel. Unless we go back to PPP. I kind of don't think that's the intention.... Some documents indicate that the Prefix Exclude option (RFC6603) might be required, but I don't have any more success if I request this option. FWIW, I am of course able to send a DHCPv6 solicit to arbitrary DHCPv6 servers, using a GUA destination. So assuming I can configure the client side realys, then this is a possible solution. The problem is that I need the PGW to pick up the routing somehow. I can think of a number of creative ways to do that. But I'd rather not be too creative. Doing what everyone else does is preferred. But what is that? Bjørn
