Your own DNS server on a Raspberry Pi: a recursive one with Pi-hole that drops ads and trackers on the way, or an authoritative one for your domains.
Pi-hole for the whole family
Set Pi-hole as the DNS server in your router or phone. It works away from home too when you combine it with a WireGuard VPN. Unbound can resolve the queries right on the Raspberry Pi, so they don't go to any big DNS provider.
Authoritative DNS for your domains
BIND, PowerDNS or Knot DNS run fine on a Raspberry Pi, for example as a secondary server next to your primary one. A fixed public IPv4 and IPv6 address is included.
sudo apt install knot
sudo knotc conf-check