While I know this is an old thread, I have a similar problem still today. While the end DNS filtering sites claim IPv6 support, when DNS filtering and IPv6 support are enabled, I tend to see problems with IPv6 devices joining the network. I am able to run a fully IPv6 network up until the point that I enable DNS filtering. Has anyone else run into, or solved this problem?
I am running RT-AC66U, firmware 380.61_2 and the IPv6 I am required to use is 6RD since my internet provider still does not support native IPv6.
Thank you.