Comcast issued my household a combination cable modem and router; I would have preferred just a cable modem, and to let my RT-N66U handle all the routing, but they didn't offer an alternative device in my area. So, the cable modem/router has only the telephone and the RT-N66U attached to it, I've disabled the Wi-Fi on the cable modem/router, and put the RT-N66U in a DMZ. So far, this all works well, except for IPv6. Using the auto setting, the RT-66U picks up an IPv6 address, but it doesn't...
How to subnet with IPv6 on an RT-N66U with Merlin firmware?
How to subnet with IPv6 on an RT-N66U with Merlin firmware?