Hello
I understand that ISC will be deprecated end of month.
Switching to a plugin for "legacy" purposes.
I want to know if
KEA or Dnsmasq DNS&DHCP can do the same magic that I have with ISC : prepopulation of subnet, subnet mask and available range form the LAN IPv6 ?
My ISP can change the IPv6 from time to time and this functionnality from ISC is a game changer in my case
Thanks for help
If you have a changing prefix use dnsmasq for dhcpv6, it can construct from a partial prefix:
https://docs.opnsense.org/manual/dnsmasq.html#dhcpv6-and-router-advertisements
There is a problem with your approach with ISC DHCPv6 as well: The prefix change will potentially go unnoticed for as long as your lease time, because your clients will use the old prefix for as long.
With dynamic IPv6 prefixes, you basically have two choices:
a. Use SLAAC in "assisted" mode, where DHCPv6 only supplies the DNS server (besides RDNSS) - if at all, because DNSv4 is sufficient to supply both IPv4 and IPv6 resolution. This is the safest/easiest approach and shown here (https://forum.opnsense.org/index.php?topic=45822.0). Any local traffic is done via IPv4, such that you do not need DHCPv6 to supply specific IPv6 to your devices in order to adress those in DNS.
b. If you need to have fixed IPv6, you will need to use some adresses on top of GUA that you can use for internal DNS purposes. Keep in mind that LUA will probably not work, because it is prioritized lower than even IPv4. Still, you can use any unused IPv6 prefix.