IPv6 prefix delegation supported?

Hi there,

is IPv6 prefix delegation supported on EC25 and RM502QAE modems? We’d like to have /64 assigned to WAN and /48 per prefix delegation assigned to LAN.

I am not sure if prefix delegation is implemented.

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Hi breti,
Our module support this feature, but your SIM card should support IPV6 network firstly, thank you.

Hi Duncan,
thanks for getting back to me. Yes, we are working on IPv6 connectivity with our own APN tunneled to our network.

Hi! I’m also interested in this feature. Do you have any details/documentation wrt what you mean by “supported”?

We do have the basic dual-stack with a PGW assigned /64 available to the modem and host(s) behind it. But it’s unclear to me how to get from there to a short DHPCv6 PD assigned prefix.

I know I can send a DHCPv6 solicit to the PGW, or a server behind the PGW, from a client on the USB side of the modem by addressing the solicit to a routable destination. E.g a GUA of the DHCPv6 server or a site-local multicast address like the “All_DHCP_Servers” (ff05::1:3). Such solicits can be sent from a client source address taken out of the PGW assigned /64. But that’s non-default client behaviour requiring explicit client configuration. Is there a way to configure the modem firmware to act on DHCPv6 PD solicits received over the USB interface, addressed to the “All_DHCP_Relay_Agents_and_Servers” multicast address (ff02::1:2)? And most likely sourced from a link local address local to the USB session between client (USB host) and modem (USB device). I guess that would mean either a proxying DHCPv6 server or a DHCPv6 relay running in the modem firmware, since those DHCPv6 solicits are unroutable?

One proposed address assignment method in 3GPP networks lets the PGW carve the initial /64 from a shorter prefix, and then reply with the shorter prefix to a later DHCPv6 PD solicit from the UE. This is best described in section 3.3 of RFC6653 ( RFC 6653 - DHCPv6 Prefix Delegation in Long-Term Evolution (LTE) Networks ) referring to TS 23.401.

A USB attached modem will be the UE (or MN in RFC-speak) in this context. The USB host can only request actions from the modem firmware. It cannot directly affect the network attach or send any link-local IPv6 packets over the tunnel to the PGW (AR), like the RFC assumes. Is there any functionality in the Quetel modem which the host can request to get the behaviour described in RFC6653? AT commands, MBIM services or QMI requests - I’m fine with anything :slight_smile:

Is there some “best practice” document on how to configure DHCPv6 PD with e.g a /48 prefix assigned to a host using a Quectel modem?

No documentation pointers or anything?

Did anyone get prefix delegation working?