Network Firewall
cybersecurity

What Is A Network Firewall And How Does It Work

The Internet has emerged as the most fruitful technological innovation in the last couple of decades. On one hand, it has opened doors to a whole new world of opportunities and simplified lives of its users. At the same time, it has made it extremely easy for cybercriminals to lay their hands on confidential data, information and files. In order to protect your digital life from all these threats, cybersecurity experts work round the clock for developing unrelenting security solutions. One of the most crucial cybersecurity solutions is Network Firewall. In fact, it is the very first line of defence to safeguard your digital life.

Understand About Network Firewall

A Network Firewall is a dedicated cybersecurity solution system designed to safeguard Internet Networks from unauthorized access. This cutting-edge cybersecurity tool monitors your Network’s incoming and outgoing traffic on a real-time basis. Based on the pre-decided set of rules, it determines to allow or block specific traffic to guarantee unbeatable security cover. All the traffic has to pass through it for an airtight environment that allows restricted access to the Internet. In other words, it filters the traffic on a Network for a fully secure computing environment. It separates Network Nodes from different sources like Internal/ External Traffic and Specific Applications. In this way, it extends holistic protection to all the Devices hooked to your Internet Connection. Most businesses, homes, schools, and intranets that set up private networks make use of this outstanding security solution.


Network Firewalls are available in the form of hardware or software solution or a well-integrated combination of both. They are a vital component in your cybersecurity mechanism. It performs a wide range of security functions. Some of the most important functions of these ingenious tools are listed below.

Types Of Network Firewall

Network Firewalls are available in a variety of versions to suit specific threat requirements.
  • Application-layer Firewalls
  • Packet Filtering Firewalls
  • Circuit-level Firewalls
  • Proxy Server Firewalls
  • Reverse-Proxy Firewalls
  • Next Generation Firewalls (NGFW)
  • Stateful Firewalls
  • Unified Threat Management (UTM) Firewall
  • Threat-focused NGFW
  • Virtual Firewall

How Does It Work?

Network Firewall is configured to keep a constant eye on the Incoming and Outgoing Traffic on your Network. In other words, it regulates and monitors the traffic to allow only the traffic that fulfills the pre-set security criteria. It acts like a Security Guard that sits at the entry point of your Network and restricts unauthorized access.

This sophisticated security tool compares the network traffic against a predefined set of permission rules. Based on this comparison, it permits the traffic that matches this criteria. At the same time, it blocks the traffic that fails to fulfill the specified security protocols. For instance, the Network Administrator of a business organization may set a rule that employees of your HR Department cannot access data from Code Server or cannot access any Gaming Websites. In other words, you can set rules as per your necessity and security policies for permitting or restricting access.

In order to understand it more clearly, you must remember that Network Traffic is either Outgoing or Incoming. Network Firewalls are capable of maintaining a distinct set of rules for both kinds of traffic. By setting up rules for the Outgoing Traffic, you get complete control over the data or information that goes out. As such, you can avoid any potential security breach and ensure unbeatable security.

Incoming Traffic is much more dangerous and requires an entirely different treatment. All the traffic reaching your Network Firewall encounters one of its prominent Transport Layer protocols known as TCP, UDP or ICMP. These protocols contain a Source Address and destination Address. In addition to that, TCP and UDP make use of Port Numbers. Similarly, ICMP have Type Codes in place of Port Numbers. These Codes/ Numbers identify Data Packets in terms of their purpose.

Not only that, Network Firewalls usually provide a Default Policy for standard computing environments. It is particularly helpful for users who want a secure environment covering the most essential set of rules. If you opt for the Default Policy, the Network Firewall gives you the option to set it to one of the specified actions like “Accept”, “Reject” and “Drop”. In case if you set it to “Accept”. Then, it will permit any Network Communication which is not ruled by the predefined security criteria. Similarly, if it is set to “Reject”. Then, the tool will restrict all such communications.

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