What Is a Firewall? A Starting Guide to Different Types of Firewalls and Whether You Need One 

What Is a Firewall? A Starting Guide to Different Types of Firewalls and Whether You Need One 


People and companies both have a responsibility to safeguard their data considering the daily increase in the number of malicious cyber-attacks. However, there are a lot of obstacles to overcome to put the same plan into action.  

A firewall is a security tool that helps prevent unauthorised access to your network or device. This article, “What Is a Firewall,” provides comprehensive information on firewall types, their functions, uses, and how they act as protective shields for your network.

So, to begin with, let’s have a conversation about what exactly is a firewall.  


What is a firewall? 

A firewall is a piece of network security equipment that monitors both incoming and outgoing data traffic on a network and filters it based on the security policies of an organisation. It essentially functions as a firewall that separates a private internal network from the public internet. 


What does a firewall do? 

A firewall acts like a protective fence around a network, warding off unauthorised users and cyber attacks. Whether in hardware or software form, it filters network data using predefined rules. Firewalls are vital for both commercial and residential network security, with third-party solutions recommended for superior protection.


Firewalls come in varieties: different types of firewalls 

Firewalls can be established using hardware or software. Software firewalls are installed on network-connected devices, monitoring data using programs and port numbers. Hardware firewalls are positioned between the network and the router. They come in various types, each with its own construction, operation, and data filtering methods. Following are some examples of various types of filters: 

A) Packet filtering 

Controlling the flow of data into and out of a network is the function of a packet filtering firewall. It decides whether to allow data transfer based on factors like the source address, recipient’s address, and application protocols.

B) Proxy services firewall

When a network is protected by this type of firewall, messages are screened at the application layer level. A particular application serves as the bridge between two networks when utilised with a proxy firewall.  

C) Stateful inspection

This form of firewall has two options: it can allow network data to pass, or it can block it, depending on the state, port, and protocol. It now decides how to filter based on the rules and context that the user has set up.  

D) NGFW (Next Generation Firewall)

The next-generation firewall is a deep-packet inspection firewall that performs more than just port and protocol checking and blocking. It also contains information from beyond the firewall, intrusion protection, and application-level inspection. 

E) UTM “Unified Threat Management” Firewall

A UTM device combines antivirus, intrusion prevention, and stateful inspection firewall functions seamlessly. Additional services can be integrated, and cloud management is often compatible. UTMs are designed for user-friendly operation and comprehension.

F) Threat focused NGFW 

These defences are more effective in identifying and eliminating threats. They can identify evasive or suspicious activities with the aid of network and endpoint event correlation. 


So, how does a firewall work? 

As previously mentioned, private networks use firewalls to filter network traffic by assessing each type of traffic against a predefined set of rules to determine whether it should be allowed. At the point where your computer connects to the network, the firewall acts as a gatekeeper, only allowing IP addresses or sources that it knows and trusts to get through.  

The firewall allows only administrator-specified incoming traffic, distinguishing between safe and unsafe communication based on security criteria. It assesses packet parameters like source, destination, and content to block unauthorized traffic as a defense against cyberattacks. This rapid inspection capability safeguards the network from harmful traffic, identifying malware and suspicious activity.


When do we need a firewall? 

Any device that is linked to the internet is needed to have a firewall. Not only your computer, but also your phone, web hosting server, gadgets that are part of the Internet of Things (IoT), and anything else that has the capability to connect to the internet. 

Devices that lack adequate security measures make easy prey for malicious software and hackers.

Hackers can take control of your computer, install unauthorized software, access sensitive data, and even your webcam. If your web server is breached, attackers can modify your website’s look, introduce malware, manipulate admin credentials, or shut down your site. Without a firewall, your website and devices are susceptible to DDoS attacks that flood your server with bogus packets, causing internet disruptions.


Are you still unsure? Following are some things that can be prevented from happening to your website by using firewall:


Firewalls protect your system against intrusions by preventing unauthorised people from gaining quick access to your computer or server and carrying out whatever actions they choose. 


If an attacker gains access, they can send harmful malware to your computer, potentially causing data theft and spreading to other systems.

3.Brute force attacks:

Hackers who use brute force strategies will try many different combinations of usernames and passwords to uncover the login information for other users or the administrative login credentials for your account. 

4.DDoS attacks:

During a distributed denial of service assault, a flood of false data may be generated; web application firewalls can try to find this data. 


Here is hoping that you have understood what a firewall is and why you need one. A high-quality firewall is essential to protect your website and personal data. For personal use, rely on the built-in Windows firewall, common antivirus software’s application firewall, and router packet filtering for ample protection. Ensure your firewall is active, install antivirus software, and configure your router correctly—this applies to macOS users too. If you are using a Linux OS, here is a guide to configure a Linux firewall 

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