I'm a bit confused as to how to proceed. IPv6 is going to require that I start thinking differently. I have an SSH server on my LAN (with IPv6) and I'd like to be able to access it from the Internet. I know not to think of this in NAT terms but how do I open up the firewall to access that server? The IPv6 address isn't really static and I don't want to open up the entire network to SSH. I could assign and different port on the server for SSH. Can anyone point me in the correct direction?
You can use a dynamic IPv6 host alias and add a WAN rule with it to allow SSH access to the LAN address.
https://docs.opnsense.org/manual/aliases.html#dynamic-ipv6-host
Cheers,
Franco