https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-16-04
Firewall setup:
open port for udp connections: sudo ufw allow 53/udp
https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-16-04
Firewall setup:
open port for udp connections: sudo ufw allow 53/udp