I've been using IPV6 exclusively (Cloudflare DNS setup on my main home router) for a couple of years. Connection overall seems a lot more consistent, haven't had an issue in a long time. However, despite the entire premise of IPV6 existing, I still cannot play online in rF2 or any other title (Assetto Corsa etc) unless I do the same port forwarding that I did when using IPV4. IPV6 should absolutely not need ports to be forwarded, and there's no need for NAT. So why do I still need to forward ports? Appreciate any insights.
I'm not sure you need port forwarding, you surely just need to allow traffic on said ports. This is about your networking design, if you are using some kind of firewall or anything that actually filters your traffic, the default behaviour is to let everything go outside (and allow replies, statefull principle) and block anything from the outside that was not initiated by the inside. IPv6 grants you the ability to get a public IP address for everything on your private network, which is a good thing for some reasons but also a bad thing security wise. The "hidden" advantage of NAT is that it obfuscate the actual machine behind the firewall, with IPv6 you just can't, your public address is known. Keep this in mind. There is no need for NAT in IPv6 and I don't even think it is available on firewalls. Just try to figure how your network is isolated from the outside, this element (box, firewall, whatever) can surely allow external traffic to the inside on said ports.
