Better safe then sorry. Perhaps the most important tool we have available for keeping the network to authorized individuals is the firewall. The last portion of the Firefox article instructed you to reboot. I assume that have done so. The first thing to check is if the firewall has started as we instructed it to. Note that you only have to check once. If the firewall runs now, it will run for ever, regardless of how many times you reboot.
UFW
Uncomplicated FireWall. The creator of that program picked a good name. UFW is hat it states. Uncomplicated as in couldn’t be easier. So let’s see what is going on.
Type the following text string into your terminal. Reminder: ctrl+alt+t is a quick way for opening a terminal. You could also right-click and select Open Terminal Here from the pop-up.
sudo ufw status (press ENTER, provide your password and press ENTER again).
The output should say Status: active
If you prefer to check the GUFW (graphical interface of UFW) the click your start button and type firewall in to the search bar. The returned search result should give you Firewall Configuration as the top result. Click that menu entry to open the GUI.
The only thing you have to check is if the check mark is switched on. If it is to the right, you are good to go. With that out of the way, let’s move on to the next chapter and configure some packages