said by dabomb4097:
The CMTS MAC is registered to 0001C = CADANT INC. according to that site.
The router setup only has one option. "IPv6 - Automatic" Enabled or Disabled. The page also shows a DUID, which looks like a longer MAC Address or something. When this was enabled it worked fine in at my other house with the UBee modem.
There are also options for 6rd Tunnel, but this is grayed out and disabled when "IPv6 - Automatic" is Enabled and the router is in Native IPv6 mode. I understand what I am doing, and am NOT confusing Native IPv6 configurations for Tunneling configurations.
Sorry about the double post, I accidentally posted as anonymous the first time and went back and redid it after I signed in.
Thanks again for the help.
Unfortunately, if your only configuration options are as shown, then you are totally at the mercy of the Linksys automatic firmware algorithms being compatible with Comcast's native dual stack implementation. The instructions from Comcast for the Linksys E4200v2 on their »mydeviceinfo.comcast.net/?homega ··· egateway
page seems to indicate that selecting "IPv6 - Automatic" Enabled is all you need (or can) do with a Cisco/Linksys router.
In my D-Link and Netgear routers, I have to manually select DHCP settings, or Comcast's IPv6 does not work, but Cisco/Linksys does not seem to make such options available.
I have a Motorola SB6121 on a Cadant CMTS (and Comcast has said that all of their Arris/Cadant boxes are now fully IPv6 functional), so that should not be a limiting factor.
Since there are no user configurable options in the SB6121, and apparently only an "On" or "Off" option in the E3200, the only suggestion I have is to try doing a factory default reset followed by power cycles on both the modem and the router and see if that wakes some sleeping function up. If that "Hail Mary" action does not help, hopefully someone who is more familiar with your particular router will notice your thread(s) and offer some better advice.
Do the PC(s) behind your router get public IPv6 addresses, gateways, etc, but IPv6 connectivity terminates at the router? Or do the PC(s) only get private IPv4 IP addresses, gateways, etc?--
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