"
I found this execellently written manual but have not tested it:
https://www.raydak.de/blog/2025-05-25_opnsense_ipv6/
Step 5 seems to be optional.
Make sure to remove all ISC and KEA IPv6 configurations and disable their DHCPv6 services before starting to configure Dnsmasq as they would be conflicting.
Also look at https://docs.opnsense.org/manual/dnsmasq.html#dhcpv6-and-router-advertisements, 3rd "Attention" box, if you plan to do dynamic DNS registration.
Hope this helps.
https://www.raydak.de/blog/2025-05-25_opnsense_ipv6/
Step 5 seems to be optional.
Make sure to remove all ISC and KEA IPv6 configurations and disable their DHCPv6 services before starting to configure Dnsmasq as they would be conflicting.
Also look at https://docs.opnsense.org/manual/dnsmasq.html#dhcpv6-and-router-advertisements, 3rd "Attention" box, if you plan to do dynamic DNS registration.
Hope this helps.
