systemd-resolve: fallback from resolve causes lookup of local network hosts to fail

[Joseph Yasi]

After upgrading to Ubuntu 16.10 from 16.04, DNS resolution of hosts on my local network fails.

The hosts line in /etc/nsswitch.conf is:
hosts: files mdns4_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] dns mdns4

If I change it to:
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4

I can resolve hosts on my local network. Appending .local to the hostname also allows DNS resolution since systemd-resolve returns a different error for that case.

Ex:
systemd-resolve rt-ac66u
rt-ac66u: resolve call failed: All attempts to contact name servers or networks failed

systemd-resolve rt-ac66u.local
rt-ac66u.local: resolve call failed: No appropriate name servers or networks for name found

"dig rt-ac66u" returns the correct ip.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Joseph Yasi (joe-yasi)]

I've just upgraded to zesty, and this problem is still present. Since systemd-resolved is sticking a 127.0.0.53 nameserver in resolv.conf, the problem is worse. To work around it, I have to replace resolv.conf with the old dnsmasq 127.0.1.1 address instead to prevent DNS lookups from going through systemd-resolved.