I’m currently running Ubuntu 18.04 and I noticed that by default I was using systemd-resolved for DNS:
stanislas@xps ~> cat /etc/resolv.conf # This file is managed by man:systemd-resolved(8). Do not edit. # # This is a dynamic resolv.conf file for connecting local clients to the # internal DNS stub resolver of systemd-resolved. This file lists all # configured search domains. # # Run "systemd-resolve --status" to see details about the uplink DNS servers # currently in use. # # Third party programs must not access this file directly, but only through the # symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way, # replace this symlink by a static file or a different symlink. # # See man:systemd-resolved.service(8) for details about the supported modes of # operation for /etc/resolv.conf. nameserver 127.0.0.53
Most of the recent systemd distributions use it, Ubuntu does since 16.10. It has the same role as dnsmasq.
By playing around a bit with the service, I noticed DNSSEC checking was disabled:
stanislas@xps ~> systemd-resolve --status | grep DNSSEC DNSSEC NTA: 10.in-addr.arpa DNSSEC setting: no DNSSEC supported: no
It was confirmed by the config file:
stanislas@xps ~> grep DNSSEC /etc/systemd/resolved.conf #DNSSEC=
Which I modified to
After restarting the service, I was able to confirm that I was now verifying DNSSEC!
sudo systemctl restart systemd-resolved
stanislas@xps ~> systemd-resolve --status | grep DNSSEC DNSSEC NTA: 10.in-addr.arpa DNSSEC setting: yes DNSSEC supported: yes
stanislas@xps ~> dig www.dnssec-failed.org | grep status ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 50750