How to use Firestarter to setup a firewall in Ubuntu

Firewalls are security programs that block connections to your computer from unknown sources. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet.

For example, all messages entering or leaving your network will pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

To run Firestarter in Ubuntu, go to the command prompt and execute $sudo apt-get install firestarter

At the prompt, it will ask if you want to continue. Enter “y” then watch the terminal as it displays progress on the downloaded package.

Then open Firestarter under the System > Administration menu

The Firestarter wizard interface will open. Click forward to begin the steps.

The first step will ask about your network setup. Choose your setup from the dropdown choices. Choose eth0 if you have a cable modem or a DSL connection otherwise choose ppp0 if your ISP uses PPPoE protocol.

The next step is about Internet connection setup. Check the box if you are sharing Internet connection on your local network.

After that you should see the main firewall interface. It will shows you the status, events and policies that you defined. It has a dashboard for inbound and outbound traffic so you can see real-time the activity of your network.

To define a new rule or policy, click the Policy tab then click the “+” button. Enter the IP, host or network name that you want to allow or not allow then click the Add button.

You should see the entered name under the policy list. You can always edit the list by using the add, remove and edit icons at the upper part of the window.

You can make inbound and outbound policies using this firewall software. You can also stop and start the firewall at any time you want. Make sure to use this tool to make effective firewall policies in Ubuntu.