What Is a Network Firewall? Ultimate Guide

A network firewall is a piece of firmware or software that manages and monitors the rules regarding which type of data packets may pass into a network, as well as other aspects of network security. A network firewall is a crucial building block of any enterprise’s cybersecurity infrastructure.

These firewalls automatically flag, tag, and restrict any unauthorized methods of network access in order to protect the data housed in the servers that keep a business running. In this article, we will take a comprehensive look at the history, structure, and feasibility of network firewalls to help you better understand how a network firewall can work for your business.

Also see: 7 Enterprise Networking Challenges 

Brief History of Firewalls

The word firewall classically referred to the walls built into a structure to contain and control the spread of a fire. Initially, these walls were designed to keep a fire from spreading past a wall of buildings, and later, engine firewalls were developed to protect passengers from catastrophic mechanical fires.

It is easy to see why, eventually, in the late 1980s, firewalls emerged alongside the early spread of the pre-Web internet as a method of protecting these fledgling networks and the important research-related data they tended to transfer.

Firewalls have grown and changed since the 1980s, but the basic function and structure has remained the same. They act to partition networks from the internet at large while admitting only authorized packets of information. There are many types of firewalls with many slight nuances, but the core of this technology remains the same.

Also see: Best Network Management Solutions 

Types of Firewalls

Firewalls are as varied as the networks they protect, but fundamentally there are two basic options when it comes to protecting a network. These two options have their pros and cons, and understanding them will aid the process of selecting a firewall solution that best suits the network in question.

Network-based firewalls

A network-based firewall is the most basic sort of firewall. A network-based firewall is positioned directly between two or more networks. This is usually the dividing line between a local area network (LAN) and a wide area network (WAN), but the contours of a network-based firewall may be defined however an enterprise sees fit.

A network-based firewall may typically be a piece of dedicated or general-purpose hardware monitoring a network’s traffic, but there are also entirely virtual network-based solutions.



Network-based firewalls are, above all, simple. By cordoning off a network from the outside world and accepting only packets from authorized senders, a network-based firewall is able to do its job with relatively little input or interference.


Network-based firewalls provide a great deal of security, especially when paired with secondary cybersecurity methods.


Network-based firewalls need only to monitor communication coming from outside of the network it is protecting. The scale of the network has a relatively low impact on a network-based firewall’s ability to monitor incoming traffic.


Dropped packages

Network-based firewalls are so simple they usually only make the decision to accept or reject a package. This means that mistagged data or important data sent from an otherwise unauthorized source will simply bounce off of the firewall, leaving the protected network unaware and unable to retrieve it.

Limited functionality

Network-based firewalls, while highly effective at efficiently tagging and blocking information, are limited in their sophistication. A network-based firewall is usually only checking for basic data like IP addresses. The data contained within packages that pass these basic checks will not be offered any scrutiny by the firewall and may slip through, unleashing malware on an unsuspecting network.

Restrictive borders

Because network-based firewalls rely on creating rigid borders between networks, any additions or subtractions to a network will require a time-consuming restructuring of the network firewall.

Also see: Top Managed Service Providers

Web application firewalls

Web application firewalls (WAF) are a type of application that deals directly with web applications. A web application firewall is positioned in front of web applications and monitors web-based traffic both incoming and outgoing.

Web application firewalls are generally “smarter” than network-based firewalls in that they analyze data more thoroughly. According to the Open Web Application Security Project (OWASP), a WAF is “a security solution on the web application level which — from a technical point of view — does not depend on the application itself.”

A web application firewall can be seen as a sort of second layer of security between any web application and the networks to which they connect. By deploying a WAF and any appropriate additional security solutions, a WAF may aid in supplying top-tier protection to an enterprise and its delicate networks.



Web application firewalls are meant to be bespoke solutions to web application network activity. Customization and specificity of functionality exist side by side with web application firewalls, and they can be updated on the fly to meet the demands of new digital threats or technology added to a network.


A web application-based firewall is built to fit around any web application, as the name suggests. This means that business conducted online via a browser can be protected no matter what the application. Complex operations that cannot afford to sequester their networks will find themselves pleased with the flexibility provided by web application firewalls.



Web application firewalls must work in conjunction with web applications. Their increased computational demand will often lead to network slowdowns. If a large network is running several web applications and exchanges a large load of data, a web application firewall may choke that system.


Web application firewalls are useful for nimble endeavors that require swift network monitoring; however, once they are scaled up and applied to dozens of applications working in concert with one another, web application firewalls tend to struggle.

Is a Network Firewall Right for Your Enterprise?

A network that works primarily internally with few or highly specific external inputs will perform well with a network firewall. A network of storage cloud servers, for instance, would take to a network firewall well.

A storage cloud network asks only for the data to be stored and outputs data that users request. The network firewalls supporting a storage cloud easily understands that packages of data will come only from authorized locations. With sufficient internal security structures, the contents of these packages can be effortlessly isolated regardless of their contents.

Networks that require constant, complex exchange of data would suffer from the simplicity of a network firewall. If teams of people require fast-paced collaborative access to an organization’s network, they will find themselves frustrated by the rigidity of a network firewall.

Remote employees working from a coffee shop or sister office rather than from home may need to access a VPN to generate an authorized IP address or otherwise manage the loss of network access.

Networks that often grow and change locations will find network firewalls frustrating to work with in the long run. A network firewall wants to establish itself firmly in the space between a network and the wider internet, rapidly growing operations with networks that are constantly expanding.

Startups and mid-sized enterprises teetering on a growth spurt should be aware of the limitations of network-based firewalls.

Finally, consider the threats a network is most likely to fall prey to. If your enterprise’s network is primarily for the local storage of intra-office data, then a web application-based firewall that prevents phishing attacks at the source will provide much more regular and useful protection than a network firewall.

Also see: Best IoT Platforms for Device Management

Dale Jakes
Dale Jakes
Dale Jakes is a writer, social media manager, and willing to try anything once. He writes about technology, games, and music on sites all across the internet.
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