Comment 23 for bug 1624320

Today I discovered some additional information in regard to this issue.

I am using Virt-Manager and KVM, I have a Br0 bridge configured to start onboot. When this is the case name resolution as above fails.

If I delete the bridge using VMM name resolution starts working ( after a reboot ). Put the bridge back in and it fails.

I do have 3 network interfaces, 1 wlan, 1 ethernet, and and additional usb ethernet configured as eth1.

I've configured the 3 interfaces using a persistent-rules file in /etc/udev/rules.d/ so that they bind to eth0, wlan0 and eth1.

By configuring my VMM Br0 interface to Hotplug, so that it does not start onboot, this has resolved the issue. However, on Ubuntu 16.04 everything worked as expected including having the Br0 bridge start onboot.

Can't say I understand what magic SystemD witchcraft is going up here, but I hope the above info provides some useful clues.