I upgraded to gig service and had to get a new modem. After the new modem was installed, I am able to statically assign ipv6 addresses and get out to the Internet. When I attempt to use dhcpv6-pd from my router, that's when it all falls apart. I have reconfigured it several times. I receive addresses on the LAN interfaces, but I can't ping out from the router (and I CAN ping the fe80 address of the gateway). IF I tell my router to pull a WAN address, I am able to ping out from the router, but not from the LAN. None of my client devices are getting traffic to them from ipv6. This is unacceptable. I use the ipv6 heavily and this is directly impacting my ability to work.
You can't just post a question like that and assume Comcast is going to fix it for you. This is a user-driven forum not a Comcast employee support forum. None of us can look up your account and see what kind of cable modem you are using.
You need to post the following for any help:
1) The MODEL number of the cable modem you are using
2) The MAKE and MODEL number of any router you are using in between the cable modem and your internal LAN
3) whether you have a static IPv4 assignment or not (if you do not then you do not have a static IPv6 assignment)
4) The operating system in use on whatever device on your internal LAN you are testing with.
Please be advised that manufacturer-proprietary firmware on your router MAY NOT properly support IPv6 DHCP-PD You will have "controllable" results if you either run Openwrt or ddwrt firmware on your router, or you use a Unix system with 2 network adapters in it as your router.