Originally published at: https://www.cyberciti.biz/faq/howto-open-dns-port-53-using-ufw-ubuntu-debian/
How do I allow incoming DNS tcp/udp port 53 connections from a specific IP address or subnet on a Ubuntu or Debian Linux server using ufw? How can I open DNS port 53 using ufw firewall? Introduction: UFW is an acronym for uncomplicated firewall. It is used for managing a Linux firewall and aims to…