When the network interface providing dns is managed by network manager, dns fails on relaunch of the interface

test dns:
dig x$(date +%N).blogspot.com +short
if it fails, there is no output

verify that Internet is available:
dig @8.8.8.8 x$(date +%N).blogspot.com +short
blogspot.l.googleusercontent.com.
216.58.194.129

provoke the problem:
- unplug and re-plug the network interface (usb Ethernet)
- or resume from standby

quick-fix to regain working dns: restart Network Manager
sudo systemctl restart NetworkManager
- dns now works again

Cause: for Ubuntu 16.10 Yakketi, this appeared shortly before 160926
probably with network-manager package 1.2.2-0ubuntu8

It appears the problem is fixed permanently by installing an old version of network-manager
wget https://launchpad.net/ubuntu/+source/network-manager/1.2.2-0ubuntu4/+build/10026930/+files/network-manager_1.2.2-0ubuntu4_amd64.deb
sudo dpkg -i network-manager_1.2.2-0ubuntu4_amd64.deb
- this completes for 16.10 on 161112

dns appears to be ok, it's just not working
for example, one can do:
nmcli d show | grep DNS
IP4.DNS[1]: 192.168.1.15

the Network Manager-provided dnsmasq is just not using that dns server that network manager knows about.

https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1629620