What are the ways to protect the local IPv6 network behind the router?

Question

ASUS

There is a real IPv4. I set up IPv6 through the 6to4 tunnel in the firmware from enthusiasts on the wl500gP and now I have real IPv6 addresses on all devices on the local network.

I want the local network to be isolated from the outside world. Tell me how to drive this whole thing under NAT, under gray IP?

Are there other ways to secure a local IPv6 network behind a router?

Answer 1

One of the mechanisms is to change the ipv6 address every 2 hours.
+ configure firewall for stateful connections

Answer 2

read about ipv6, there are no gray addresses as such, you can simply restrict access to segments.