Finally got the nameserver replaced today, after several days of struggle spread over recent weeks. I used a Raspberry Pi running Debian Stretch, which, though it may sound under-powered, is actually running at a clock-speed 1.5 times the old server, which was a re-purposed thin client. Our small domain has a very light DNS load, but I prefer to have it running on its own box, and not to have all the critical eggs in one basket.
Anyway, I struggled a bit to get the zone files served correctly, since a few things had changed since the old server. At first named was failing to start, and then I was getting SERVFAIL errors on authoritative lookups. I learned new things and have a better understanding of dns, systemd, and iptables after this experience.
