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Ubuntu Firewall Configuration program lets you turn on, make custom rules, and better secure Ubuntu, and manage its built-in Firewall.
Go to Applications Menu on the top left of your screen then click on “Ubuntu Software Center” and type firewall in the searchbox. Pick firewall configuration then use the Ubuntu Software Center Wizard to install it.
The Ubuntu firewall configuration program is located in Systems > Administration sub menu. You can use Firewall configuration to enable and disable the firewall, and make firewall rules for Ubuntu.