With my ubuntu 16.04, my /etc/resolv.conf change every system start
cat /etc/resolv.conf
nameserver 127.0.0.1
Network-manager have the correct dns name server 192.168.1.1
I removed bind9 and all related packages.
No special config on rc folders nor rc.local
No dns-nameserver options with /etc/network/interfaces.
I missed something? What app can change this file automatically?