What happens if you turn your Firewall On/Off ?

Guest | January 15, 2012 | Comments (0)

In this post I will explain that why a firewall is important in our computer system and why we should keep the Firewall turned ON. I have used some images/screenshots to provide a thorough explanation.

But before we start, it would be beneficial to know What is a Firewall?

A firewall is a software program that has the ability to help prevent hackers or malicious software from gaining access to your computer through a network.
A firewall can also help you to stop your computer from unknowingly sending malicious software to other computers.

Here i have used :

Vmplayer
Windows OS
Backtrack 5 OS

We have created a second machine virtually on the windows OS, so now the backtrack OS and Windows OS are working as two separate computers, in essence, it is like having two laptops connected on a network.

Now lets start the process.

In this image ipv4 addresses are shown. Check the yellow boxes which I have highlighted. This is the image before turning off the firewall .

Now I am going to turn off my windows firewall.

Here we have turned off the firewall . Now check can our systems ping each other ?

Yes, both the system are pinging and can communicate over the network.

Note : If you want to ping two systems then it is important to turn off your Firewall. Otherwise, your firewall blocks all incoming ICMP requests which are sent by other system .

Now, lets check what happens when I turn my Windows firewall ON. As i clearly stated above if we turned ON the firewall, the two systems won’t ping. Let’s check if it is right.

Step 1: To Turn on firewall-go to control panel>Firewall>Turn on firewall.

Now your Windows XP firewall is turned on.It is the time to ping .

It is not pinging ,when i ping from XP, it is pinging because the backtrack firewall is not ON but when I turned ON the Windows XP firewall and ping from backtrack it is not pinging , that shows that if we keep the firewall turned ON our computer will be secure from unknown ICMP requests or unknown incoming requests (which want to gain unauthorized access your system).

What happens if we leave Firewall turned off all the time?

Leaving the firewall off is like an invitation for hackers to come and steal all your data and hijack your system.

Advantages of Firewall :

You can monitor incoming and outgoing security alerts.
All firewalls can be tested for effectiveness by using products that test for leaks or probe for open ports.

Disadvantages of Firewall :