resolved.conf — Network Name Resolution configuration file
/etc/systemd/resolved.conf
When starting, systemd-resolved will read the
configuration file resolved.conf.
This configuration file determines the fallback DNS
servers.
DNS=¶A space separated list of IPv4 and IPv6 addresses to be used as the fallback DNS servers. Note that the servers obtained from systemd-networkd.service(8) take precedence. If this option is not given, a compiled-in list of DNS servers is used instead.