Went back to ISC from Kea

Turned on the Kea DHCP server when I updated to 24.11. Had a power outage a couple of days later that ran longer than the UPS. When things came back up, nothing could resolve local hostnames other than the static assignments.

I found that there were a few checkboxes that were no longer set (DNS Registration and Early DNS Registration). Even after flipping those and restarting both DHCP and DNS, resolution wasn't working because everything has caches that last a little too long. Dropping everybody's connection (switch and AP reboots) got them fixed.

This sucked and caused some extra hours of downtime. I flipped the setting back to ISC because it just worked, no nonsense. Googling for info on this Kea migration brings up primarily "it's beta" and other excuses why some feature is not working, not a single "it's now 100% and we're confident."