Dynamic DNS with IPv6 Prefix Delegation on OPNsense — Why the UI Isn’t Enough
The OPNsense built-in Dynamic DNS UI fails silently with IPv6 prefix delegation over PPPoE — it looks for a host address on an interface that doesn’t have one. This post shows how to read the delegated prefix from the FreeBSD routing table, update multiple dynv6 hostnames with proper change detection, and wire everything into the OPNsense cron UI via configd.