Imagine our houses without a fence or boundary wall. This would make our property easily accessible to trespassers and robbers and place our homes at great risk, right? Hence, fencing our property helps safeguard it and keeps trespassers at bay. Similarly, imagine our computers and networks without protection. This would increase the probability of hackers infiltrating our networks. 

To overcome this challenge, just like how boundary walls protect our houses, a virtual wall helps safeguard and secure our devices from intruders, and such a wall is known as a firewall. 

What is Firewall?

Firewalls are security devices that filter the incoming and outgoing traffic within a private network. For example, if you were to visit your friend who lives in a gated community, you would first take permission from the security guard. The security guard would check with your friend if you should be allowed entry or not. If all goes well, your access is granted. On the other hand, the security guard would not grant permission to a trespasser looking to enter the same premises.

Here, the entry access depends solely on your friend, the resident's discretion. The role of the security guard, in this case, is similar to that of a firewall. The firewall works like a gatekeeper at your computer's entry point, which only welcomes incoming traffic that it has been configured to accept. 

Firewall for dummies

Firewalls filter the network traffic within your network and analyzes which traffic should be allowed or restricted, based on a set of rules in order to spot and prevent cyber attacks. Your computer communicates with the internet in the form of network packets that hold details like the source address, destination address, and information. These network packets enter your computer through ports. The firewall works on a set of rules based on the details of these network packets, like their source address, a destination address, content, and port numbers. Only trusted traffic sources or IP addresses are allowed to enter your network. When you connect your computer to the internet, there is a high chance of hackers infiltrating your network. This is when a firewall comes to your rescue by acting as a barrier between your computer and the internet. The firewall rejects the malicious data packet and thus protects your network from hackers.

On the other hand, traffic from trusted websites is allowed access to your network. This way, the firewall carries out quick assessments to detect malware and other suspicious activities, thereby protecting your network from being susceptible to a cyber attack. 

Types of Firewall 

Firewalls can either be hardware or software. Software firewalls are programs installed on each computer. This is also called a host firewall. Meanwhile, hardware firewalls are equipments that are established between the gateway and your network. Linksys routers are a good example of a hardware firewall. Besides this, there are other types of firewalls designed based on their traffic filtering methods, structure, and functionality. 

The firewall that compares each outgoing and incoming network packet to a set of established rules such as the allowed IP addresses, IP protocols, port number, and other aspects of the packet is known as a packet filtering firewall. If the incoming network traffic is not per the predefined rules, that traffic is blocked. A variant of the packet filtering firewall is the stateful inspection firewall. These types of firewalls not only examine each network packet, but also checks whether or not that network packet is part of an established network connection. Such firewalls are also referred to as dynamic packet filtering firewalls. 

Our next type of firewall is called a proxy firewall. This draws close comparison to how you give proxy attendance for a friend. Like how you take the authority to represent your friend, the proxy firewall pretends to be you and interacts with the internet. They come between you and the internet and thereby prevents direct connections. This protects your device's identity and keeps the network safe from potential attacks. Only if the incoming data packet contents are protected, the proxy firewall transfers it to you. They are also known as application-level gateway. A firewall can spot malicious actions and block your computer from receiving data packets from harmful sources. In addition to preventing cyber attacks, firewalls are also used in educational institutions and offices to restrict users' access to certain websites or applications. It is used to avoid access to unauthorized content.

So here's a question for you. Which firewall is also known as application-level gateway? 

A. Proxy firewalls 

B. Stateful inspection firewalls 

C. Packet filtering firewalls 

D. Dynamic packet filtering firewalls 

Do give it a thought and leave your answers in the comments section below. Three lucky winners will receive Amazon gift vouchers. Cyber crimes are today making headlines every day. And individuals and companies must do everything possible to secure their information. Hence, using security devices like firewall that will help them in safeguarding their network and computers.

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