I’m using a T-Mobile internet SIM in an M.2 to RJ45 Sled with a RM520N-GL. I’m connecting via ethernet to a Wifi Router (Ubiquiti Dream Machine, UDM) for my house. When I enable SLAAC, it creates an IPv6 Proxy to provide IPv6 address and routing for the rest of my network. This only works with the T-Mobile provided gateways (all of them), not the Quectel card. The UDM does get an IPv6 address and can ping from there out, but I can’t get the network behind it to work with it. I can help debug the differences between the two devices, but not knowledgeable enough in IPv6 SLAAC/DHCPv6 to know what is wrong.
Additional info:
AT+QCFG=“usbnet”
+QCFG: “usbnet”,0
T-Mobile IPv6:
SLAAC based, no DHCPv6-PD available.
Running NAT mode on the RM520, but IPPT also doesn’t work in the exact same way. (i.e. device on ethernet gets IPv6, devices behind router get IPv6, but no routes are available to work through router.)
I think this is related to this thread: