[throw0101a]

> NAPTv4 with a "block incoming connection" side effect is widely deployed, running on countless CPEs. Proper IPv6 firewall is not.

I've been running IPv6 through my Asus for years now and it's been no different than IPv4. Going to Advanced Settings > Firewall, under "IPv6 Firewall" it says:

> All outbound traffic coming from IPv6 hosts on your LAN is allowed, as well as related inbound traffic. Any other inbound traffic must be specifically allowed here.

It then has a table where you specify traffic to be allowed in to specific internal hosts on particular port (ranges), but since this is IPv6, you don't have to deal with reverse-NATing now.

* https://www.asus.com/us/support/FAQ/1013638/