UFW, which stands for Uncomplicated Firewall, is a user-friendly front-end for managing IPTables. It is the primary firewall used across UTN systems.
Commonly allowed ports/services, also known as rules, on most UTN systems (applicable to both IPv4 and IPv6) include:
ssh: Allows SSH access to the server.80/tcp: Permits HTTP traffic to the server.443/tcp: Enables HTTPS traffic to the server.
Avoid enabling 25/tcp for SMTP traffic unless the mail server (
Postfix) is properly secured against unauthorized access.
Useful Commands #
Here are some essential UFW commands to remember:
ufw allow [rule]: Opens the firewall to allow traffic that matches the specified rule.ufw delete allow [rule]: Removes an allow rule that was previously set.ufw show added: Displays the rules that will be activated upon the next reload.ufw enable: Activates the UFW firewall.ufw status: Shows the rules currently enforced by the firewall.
Execute these commands with root privileges.