I can no longer browse http://ipv6.whatismyv6.com, and the Comcast IPv6 Test at http://test-ipv6.comcast.net fails. My router shows that Comcast is no longer assigning an IPv6 address to my router or /64 prefix delegation for my local network. The issue started on Monday 01/15/2018. Then a few days later I could browse http://ipv6.whatismyv6.com again, and the Comcast IPv6 Test at http://test-ipv6.comcast.net passed. Then the issue started again on Monday 01/22/2018, and I can no longer browse http://ipv6.whatismyv6.com, and the Comcast IPv6 Test at http://test-ipv6.comcast.net fails (see screenshots below).
I have a Zoom 5370 modem which is on Xfinity's list of approved modems according to the link below. I also have a TP-Link Archer C1200 router. I have had this combination since early 2016 and never had any IPv6 problems before. I connected my laptop directly to the modem, and Comcast also does not assign an IPv6 address to my latptop. I have also power cycled my modem and router multiple times to no avail. I also contacted Comcast support, and they took me through all the basic troubleshooting steps and also reset my modem to no avail. I need IPv6 for work. Can someone please help?
Solved! Go to Solution.
My IPv6 issues have been completely resolved. The problem turned out to be a recent firmware upgrade on my TP-Link Archer C1200 router which I have since replaced with an ASUS RT-AC66U_B1 router. IPv6 now works reliably, and I always get the same IPv6 LAN prefix delegation after multiple reboots. The ASUS RT-AC66U_B1 also supports IPv6 firewall rules, and with stable LAN prefix delegation, I can finally enable IPv6 access for my personal (non-business) web server. The TP-Link Archer C1200 also seems to have been the problem with receiving random IPv6 LAN prefix-delegation networks after reboots and power failures.