IPv6 keep disabled when WAN type is set to "USB"

[qakcn]

I am using Android Phone as USB modem to access Internet. WAN type is set to "USB".

On my previous router, Asus RT-AC56U, IPv6 worked fine. I set IPv6 "Connection type" to "Passthrough", and the devices connected to the router could get the IPv6 prefix correctly and access Internet through IPv6.

Bu after my replaced my router to new Asus RT-AC86U, it no longer worked. Checked the "IPv6" page in the "System Log", the "IPv6 Connection Type" stuck to "Disabled".



Using Merlin doesn't fix the problem.

Please help, thanks.

 

[qakcn]

Nobody knows how to solve this?

 

[appleseed]

View attachment 18424

check here since you have a /0: https://www.snbforums.com/threads/setting-up-ipv6-on-a-rt-ac68u.27418/
and optionally, restarting both the router and cell phone is probably a good way to rule out other possibilities

I believe LAN IPv6 Prefix /0 is no good. You want /64. A bit more info from this thread.

 

[qakcn]

check here since you have a /0: https://www.snbforums.com/threads/setting-up-ipv6-on-a-rt-ac68u.27418/
and optionally, restarting both the router and cell phone is probably a good way to rule out other possibilities

This doesn't work. When WAN type is USB and IPv6 Connection type is Passthrough, IPv6 Connection type in System Log shows Disabled. This is only bad on AC86U.

The same configurations works fine on AC56U, router can assign a 240x:: IPv6 address, and LAN devices can assign a /64 prefix. Visiting Internet through IPv6 is available.

Restarting does no help. I even reset the phone and the router to factory default.

I can assure this is a problem in the firmware.