Client IPv6 unable to access internet on Windows Server 2019 Essentials with RT-AC86U AsusWRT Firmware 3.0.0.4.386_51925

[GAndreone]

This issue is very similar to Have global ipv6 address but unable to access internet over ipv6 with these major differences.

1) The server has both an Intranet and Internet NIC. The RT-AC86U is attached to the Internet NIC. The server itselff has full access to the Internet via IPv4 and IPv6. From the Router, pings of ipv6.google.com are successful.

2) Packets from the Clients are sent to the Internet NIC via RRAS and are received by the Internet NIC as verified by Wireshark. When pinging ipv6.google.com from the Client "no response found" at the Router.

3) I suspect that the RT-AC86U is blocking outgoing packets that do not originate from the Internet NIC. Since the firmware is similar to Merlin perhaps this can be confirmed. If true, can this response be modified?

4) Is there a way to modify the IPv6 firewall using the Protocol option "Other" to specify ICMPv6 paramters.

5) Would changing the firmware to ASUSWRT-Merlin resolve the issue?

 

[sfx2000]

Sounds like a bad route on the client interface on your Win2019 server...

I don't know enough about WinServer - but couple of things that might help...

Configure IPv6 for advanced users - Windows Server

Provides step-by-step guidance for how to use the Windows registry to disable IPv6 or certain IPv6 components in Windows.

learn.microsoft.com

 

[GAndreone]

Sounds like a bad route on the client interface on your Win2019 server...

Thanks for the reply. Thats what I thought, but after over 700 pages of chatGPT I finally installed Wireshark and verified that the packets actually make it to the Router interface. The funny thing is that packets that originate on the NIC attached to the router function 100%. More simply, if I place a computer directly on the router everything is ok.

This is the same ping -6 google.com made on the Server.