I still haven’t figured out how to make a firewall rule with slaac on pfsense, with an ISP that hands out addresses at random. It’s my understanding’s slaac is the “right” way to do things, not dhcp and reservations.

Granted, it’s been a minute since I tried so I don’t remember the issues, but as I recall, when ipv6 prefix changes, device gets new IP (and it seems not just the prefix part. I can get the firewall to register IPs into DNS and use a dns based firewall rule, but unbound restarts and blows out its cache when a device joins the network. And there another part to it but it’s all gone fuzzy.