systemd-resolved is a systemd service that provides network name resolution to local applications via a D-Bus interface, the resolve NSS service, and a local DNS stub listener on 127.0.0.53.
Traditionally, /etc/resolv.conf has been used to handle name resolution. Below is an example of this file on a system that uses systemd-resolved:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN # 127.0.0.53 is the systemd-resolved stub resolver. # run "systemd-resolve --status" to see details about the actual nameservers. nameserver 127.0.0.53 search localdomain.loc
The systemd specific configuration file is /etc/systemd/resolved.conf. An example is shown below that uses Quad9 for primary DNS resolution with fallback to Google's Public DNS. The Ubuntu man page for resolve.conf is located here.
# This file is part of systemd. # # systemd is free software; you can redistribute it and/or modify it # under the terms of the GNU Lesser General Public License as published by # the Free Software Foundation; either version 2.1 of the License, or # (at your option) any later version. # # Entries in this file show the compile time defaults. # You can change settings by editing this file. # Defaults can be restored by simply deleting this file. # # See resolved.conf(5) for details [Resolve] # Use Quad9 for normal resolution DNS=188.8.131.52 184.108.40.206 # Use Google Public DNS in case of a failure of Quad9 FallbackDNS=220.127.116.11 18.104.22.168 Domains=bluecrow.net LLMNR=no MulticastDNS=no #DNSSEC=no #Cache=yes #DNSStubListener=yes