My installation story (and "possible" issues) are a little different. Original set up before Comcast Home was ARRIS 722 Cable Modem. Airport Extreme Gen 5 (supplying both a 2.4 and 5 ghz networks) connected to the Arris 722. A second Airport Extreme (Gen 2) connected to extend the original Network setup by AE Gen 5. In this case, all devices, wired and wireless were see direct IPV4 and IPV6 traffic. The Arris 722 automatically sent both sets of information to the AE Gen 5 for auto setup.
Comcast Home apparently requires its own "dedicated" wireless service I was told. The tech brought out an ARRIS TG862G (which I can log into and see). So as not to conflict with the 10.x.x.x default settings in the two AEs and existing network, the TG862 was reconfigured with a 192.168.1.1 gateway address. The AE Gen 5 is now plugged into Port 1 (the only active one I was told) of the 862.. All the XFinity Home wireless (the control panel touch screen primarily) seems happy.
All the downstream devices from the AEs are running fine with one exception. The two AEs are no longer seeing the IPV6 information. The tech called level 3 Comcast and was told that the two downstream AEs were now really just handling the home network IP addresses and that the TG862 would handle both IPV6 and IPV4 information (which when I log into it with a wireless device it does).
So the question is, am I losing anything in the two AEs in terms of original functionality? Bridge mode on the TG862 is not acceptable as the Home Security Touch Screen needs access to the TG862...
Thoughts??
Jay S.