Configuration migration advise regarding DNS/DHCP for IPv6

[sbellon]

Hi all,

I recently upgraded to OPNsense 26.1 and would like to plan for the migration away from old configuration to the newer preferred one, and I am seeking for some help and advise in doing so.

As background:

- I have a German Telekom PPPoE dual stack on WAN-side, IPv4 and IPv6 also configured on LAN side as follows.

- LAN IPv6 interface is set to Track Interface (WAN) with manual adjustment of DHCPv6 and RA.

- In Virtual IP, I have an IP Alias on LAN interface configured to some fd01:xxxx/64 ULA.

- In Router Advertisements for LAN, I have mode Stateless and OPNsense's LAN interface with the Virtual IP Alias prefix set as DNS server.

- ISC DHCPv6 is configured (to some range), also with OPNsense's LAN interface with Virtual IP Alias prefix set as DNS server.

- I am already using Dnsmasq for DNS and not Unbound.

Now my questions regarding how to migrate this setup "into the future":

1) IPv6 Configuration Type: if I understand things correctly, when doing separate DHCPv6 and RA configuration anyway, going from "Track Interface" to "Identity association" should be a simple and even recommended switch without anything else to consider?

2) Switching away from ISC DHCPv6: My question is, whether Dnsmasq is suited for (or even capable of) doing what I am doing.

Dnsmasq documentation reads: "There is support for doing address allocation (both DHCPv6 and RA) from subnets which are dynamically delegated via DHCPv6 prefix delegation."

Would that also include a Virtual IP Alias like the ULA one I am using? If not, would it work with Kea?

TIA.

Greetings,
Stefan