I use USB tethering and NetworkManager just creates a new wired connection whenever I make changes to existing one and reconnect a phone. Also I may use random WiFi spots from time to time and do not want to set up each of them. The solution for me is: [main] dns=none in /etc/NetworkManager/NetworkManager.conf and nameserver 208.67.222.222 nameserver 208.67.220.220 in /etc/resolv.conf This way NetworkManager does not overwrite resolv.conf Best regards, Max