We all have heard about firewall. Many of us have seen a small pop-up near date & time in the task bar, asking us to turn on Firewall. People who play games in LAN, have to turn off their firewall. But what is this Firewall and why is it there? How does it make any difference if it’s on or off? How will it affect your computer? Well, in this post we will discuss these questions in details and make you aware of its importance.
What is Firewall?
Firewall is not a useless thing in your system. Although you may have hardly seen it working, it is one of those few things, that work quietly in the background keeping your system safe and secure! So what is Firewall? Well to put it in very simple words:
Firewall is nothing but a barrier between your network & system and the Less trustworthy network also commonly known as Internet.
It’s job is to protect your system from the harmful malwares, spywares and viruses that can enter your system/network from various other sources. But if every time it stops a harmful program from entering and warns you about it, naïve users will panic, thinking the system is already infected. This is why it remains at the back, silently doing its job. If your machine is the Gotham city, Firewall is the Dark Knight, the Batman!
Where is Firewall installed?
Well its really up to the Network or Security architect to decide where he wants to put the Firewall. By default, each machine be it Windows or Linux has Firewall pre-installed and enabled. There are 2 ways you can use Firewall.
- Firewall between your network and the internet along with your system’s default firewall:
This is the most basic and secure architecture for all networks. In this case the threats are eliminated before they enter the network. This is a more safe and risk free approach, because even if a threat gets into network, each machine’s firewall won’t allow it inside thus keeping everyone secured from various threats.
Prominent companies use this approach, since they cannot take any risks with their data.
Network Firewall
- Only System’s default firewall:
In this case, there is no network firewall. Each machine uses its own firewall to keep itself safe and secure from various threats. But there can be times when a user turns off his firewall and never turns it on. At such times, without the network firewall the threat can easily infect that machine, and any devices connected to it.
This is generally the case in your home machines and small-scale industries and shops and cyber cafes.
To check your system’s Firewall go to ‘Control Panel –> All Control Panel Items –> Windows Firewall’. You see the current status of Firewall and various options to configure it as per your needs.
Firewall settings in Windows
How Firewall works?
As stated above, the role of Firewall is to protect and secure the network from malicious programs and softwares. It does so by filtering all the traffic between the unsecured outside network and the internal network. An antivirus program is installed on it to help it with scanning the incoming and outgoing patters for virus signatures. It checks each packet going in (from internet to LAN) or out (from LAN to internet) . Many a times, attackers send virus in various packets which then gets joined after receiving. To avoid this, Firewall checks the parts of packets first and then the packet as a whole for virus or malicious code.
Installing a Firewall also restricts any outsider to use any program in your machine. This is why, generally during LAN gaming, where each machine needs access of other, Firewall is turned off. There are some pre-defined programs which the Firewall doesn’t check. Firewall keeps a list of these programs. You can add programs that you trust, and Firewall won’t check it at all. To add a program to exceptions select ‘Allow an app or feature through Windows Firewall’ in Firewall settings.
Allow a program through firewall
Types of Firewall!
There are 5 common types of Firewalls, namely:
- Guards: Receives data packets, interprets them and forwards using same protocols . More security and restrictions.
- Application Proxies: Helps user to define the rules, and follows those rules with no exceptions. Eg: Govt. Database Units, you can view but not edit the entries.
- Personal Firewalls: Used in home PCs, you can manually set programs you want to allow through it.
- Packet Filtering Gateways: Separates Network from Internet and only allows packets that belong to same organization but different network.
- Stateful Inspection Firewall: Checks packets in group instead of checking it individually.