systemd-resolved
From NixOS Wiki
systemd-resolved is a systemd service that provides network name resolution to local applications via a D-Bus interface, the resolve NSS service (nss-resolve(8)), and a local DNS stub listener on 127.0.0.53. See systemd-resolved(8) for the usage.
Configuration
The following configuration configures resolved daemon to use the public DNS resolver provided by Cloudflare. DNSSEC and DNS-over-TLS is enabled for authenticity and encryption.
networking.nameservers = [ "1.1.1.1#one.one.one.one" "1.0.0.1#one.one.one.one" ];
services.resolved = {
enable = true;
dnssec = "true";
domains = [ "~." ];
fallbackDns = [ "1.1.1.1#one.one.one.one" "1.0.0.1#one.one.one.one" ];
dnsovertls = "true";
};