IPv6 Passthrough failure on USB WAN

[vesati]

I have an Asus GT-AX6000 running Merlin 388.6_2_rog, and I am using a USB modem as my primary WAN.

The router is receiving an IPv6 address from the network (T-Mobile), and I can ping IPv6 addresses from the router over the WAN interface.

I have IPv6 passthrough enabled on the router, and devices on my network are receiving public IPv6 addresses from T-Mobile through the router.

The problem is that I can't ping IPv6 addresses from any client devices on my network; the devices are assigned public IPv6 addresses by T-Mobile, but the router is not passing IPv6 traffic from my network to T-Mobile.

Is this a known bug, is there a fix for this, or is a fix on the roadmap?

 

[DJones]

Is Respond ICMP Echo (ping) Request from WAN enabled? Firewall -> general.

 

[vesati]

Is Respond ICMP Echo (ping) Request from WAN enabled? Firewall -> general.

No. I thought that was generally considered a bad practice.

I should add for clarification that this same modem, when connected by ethernet to the Asus router over the WAN port has no problem passing IPv6 traffic to the router and client devices connected to the router.

Additionally, when the modem is connected via USB to other routers (GL.iNet, for example), it can pass IPv6 traffic.

It only appears to be an issue passing IPv6 traffic when connected to the Asus router via USB.

 

[DJones]

Ah ok so you can ping between clients, just not out from clients. The reason I said that is I think dhcpv6 pass-through is serving the clients from the modem I believe which is on the other side of the firewall. I could easily be mistaken. Ipv6 isn’t my strongest knowledge. Just curious if ping functions if you try and enable it. But yes normally it’s not best practice.

 

[Analog-1]

The reason I said that is I think dhcpv6 pass-through is serving the clients from the modem

Yes using passthrough from the Asus router is just that passthrough nothing more. There is no firewall involved on the Asus side.