I have DPC3939B cable modem and have ben sucessfully using ipv6 for some time. The cable modem, for the past 2 years (or more) has been assigning two subnets form our zzzz:xxxx:yyyy:1300/56 prefix deligation. Those subnets have been zzzz:xxxx:yyyy:13e0/64 and zzzz:xxxx:yyyy:13e1/64.
After a router reboot (not modem reboot, but our internal router), the cable modem is now assigning 13c0/64 and 13c1/64.
This has messed up all of our staticly assigned IP adresses to various servers and subsequent DNS assignments. Now I am faced with many hours of work to correct the issue.
How can I get my cable modem to go back to assigning the 13e0/64 and 13e1/64 subnets to my router?
I just finished getting new static IPv6 addresses assigned to our various servers and have things working again.
So I'd like to change my question from 'how to go back to the previous subnet assignment' to 'How do I prevent the cable modem from changing the ipv6 subnet assignments?'
Hi there, thanks so much for taking the time to reach out to the Digital Care Team and I am so glad that you were able to get the issue resolved with the static IP addresses. You have reached the right team to help address your second concern. Can you please send us a private message with your name, the full address, and the account number?