Comcast has finally gotten around to giving hosts inside the firewall publicly routable IPv6 addresses, but port forwarding (which, by the way, can only be done through Xfinity's website or mobile app which then connect to and configure the router through the ISP interface -- if you go to the port forward configuration in the router's webui, all you'll see is a message that it's now "easier than ever" to configure port forwards) can only happen on IPv4. Want to open a hole in the IPv6 firewall? Well that's just too fucken bad.