When you google what is a firewall, you get a Wikipedia page that tells about the firewall. According to Wikipedia firewall is –
In computing, a firewall is a
- network security system that controls the incoming and outgoing network traffic based on an applied rule set.
- establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is assumed not to be secure and trusted.
- exist both as software to run on general purpose hardware and as a hardware appliance.
Many hardware-based firewalls also offer other functionality to the internal network they protect, such as acting as a DHCP server for that network.
Firewall simply acts as a protection between a computer and network.
Computers are connected to each other and they share data and some personal information with servers. The same way servers are connected with computers and they do share data depending on the request from the client computer. But among those millions of connections, there are dangerous connections too that steal private data from servers or desktop.
So to recognize and prevent such harmful and dangerous connections we use a firewall. We can configure rules manually about the connections or there are also default set up rules in the firewall that stop certain connections to interact with system through the network.
In Ubuntu UFW is by default installed but if you doubt then you can check it by the following command –
$ sudo dpkg --get-selections | grep ufw
Is the firewall installed? If not, you can install it from terminal.
$ sudo apt-get install ufw
Once you have installed ufw you can configure this firewall from the terminal. But ufw is known for its simplicity and ease of use. So we will use graphical user interface GUFW instead of the terminal. Yeah!
So open up software manager and search for ‘gufw’ and install it –
I am using Ubuntu so I’ll start firewall from dash.
Here we have a nice, easy to use firewall interface that everyone can understand. The interface has the following easy options –
Profile – Profile menu has some inbuilt profiles for Home (set by default), Office and Public.
Incoming and Outgoing connections for each profile –
Status – If you need to turn off the firewall, in gufw you only click this button and to turn back on clicking the button again.
Now move down the side of the application. Here we have some very simple firewall customization tools.
Listening Report – Under the listening report, we have the list of services, and applications using incoming or outgoing connections. Each service and application behaving differently and have their own set of rules and rules can be customized also.
Add a Firewall Rule – Select any service or application and click ‘plus’ sign and it will open window that is in left. The window has three tabs ‘Preconfigured’, ‘Simple’ and ‘Advanced’.
Preconfigured – Here you have preconfigured settings for applications.
After you have set up rules click Add. Rules added! You can see your added rules under Rules.
You can edit the rules and delete the rules. To edit any rule select it and click the setting icon below the list.
To delete any rule select rule and click ‘minus’.