How to Test Your Firewall

edited August 2023 in PC Tech

Firewalls are an essential part of cybersecurity for both individuals and businesses, especially in the current Internet landscape where ordinary users are increasingly susceptible to cyberattacks. But many users don’t know that firewall testing is a crucial part of network security. Read on to learn more about maintaining your home or work firewall in order so you can stay protected.

What is a firewall, and why should I test it?

Firewalls act as a barrier between your network and the internet. Firewalls filter both incoming and outgoing traffic based on predefined criteria that define suspicious activity. In doing so, they protect your devices from a security breach and safeguard access to your personal information. They come in several different varieties, including software, software as a service (SaaS), hardware, public cloud, and private cloud (virtual).

Some networks use multiple firewalls. Businesses whose networks involve many devices may implement firewalls for each specific device as well as a network for the entire network. That way, incoming and outgoing traffic needs to pass two separate barriers before being allowed entry.

Most people’s devices come with a network firewall already installed. If you’re not sure, go to the security settings on your device and check that your firewall is turned on. Unfortunately, however, ensuring the firewall is turned on does not guarantee that it’s providing optimal protection. For the most secure connection, you should conduct regular tests of your firewall.

You see, firewalls were not designed to be set up once and left alone. For optimal protection and performance, you should regularly test your home or business firewall and make sure that it is effective. You will need to edit and define your firewall settings regularly to make it effective. This practice ensures that your firewall responds and adapts to changing network conditions.

In a world where cybersecurity attacks are becoming more sophisticated and more frequent, firewall testing is a crucial step of any security plan. In addition, firewall testing is required in some contexts where your Internet usage is governed by compliance standards and regulations.

Luckily, firewall testing has evolved to meet the current demands of network security. Testing can be done for free and can evaluate various aspects of your firewall performance as well as its adherence to various standards, including HIPAA or NIST. Let’s take a closer look in the next section.

How do I check my firewall?

There are a lot of free network security firewall testing tools available that cater to the needs of a variety of connections, ranging from personal devices and business networks. You can check your firewall in a few different categories, including functionality, security, performance, and compliance.

A great way to test your network is from the Internet so that you can simulate incoming attacks. One of the most accessible and user-friendly tools for firewall testing is ShieldsUP from Gibson Research. Like any good firewall testing tool, ShieldsUP tests all of your device’s ports to ensure they’re not visible to hackers.

ShieldsUP and other similar online firewall testers tend to offer a few different network firewall tests. The common ports test evaluates some of the most common (and often most vulnerable) ports used by services like FTP and NetBIOS, ensuring they are in stealth mode and invisible to hackers using port scanning tools.

The file sharing test, on the other hand, checks for ports typically associated with hazardous or suspicious programs. If the test detects one of these programs, it means that your computer could have been infected with a hidden file server.

An all ports and services test involves all ports and checks their status: open, closed, or in stealth mode. This allows you to see which ports may be vulnerable to attack and react accordingly.

If you operate a large network and are looking for a more comprehensive security evaluation, you may want to consider hiring a professional to perform penetration testing. Though this option is clearly more expensive and time-consuming, it replicates real attacks much more closely, allowing you to detect and respond to any holes in your network security.

How should I interpret my results?

So, you’ve done all your tests: now what? What do the results mean, and how should I respond to them? With network security firewall testing, the tests themselves are just the beginning. Here are a few steps you can take after firewall testing for best results. 

First, if your tests have revealed any open ports, evaluate whether or not those ports need to be open. The more open ports you have, the more vulnerable you are to a cyberattack, so you should aim to keep as many ports in stealth mode as possible.

Secondly, evaluate whether or not the firewall performed as you expected. You may want to consider its speed, its volume capacity, its ability to prevent attacks, and its compliance with whatever standard your network uses.

Thirdly, document the results of your test. Understanding how your firewall performed in a previous test will give you more insight into how to interpret another test.

How often should I test my firewall?

You may have noticed the mention of “previous test” in the last paragraph. This is because best network security practices indicate that you should perform regular tests. The exact frequency will depend on your network and your needs.

Do you run a business with many employees and various firewalls? You may want to implement a policy requiring firewall testing every several months. Are you a personal computer user who rarely makes changes to their network? Every six months might be sufficient. In any case, remember that the higher the frequency of testing, the more secure you can feel in your network security.


Firewall testing is an important step towards increased network security in an age of digital vulnerability. Though there are more pitfalls now than ever before, the technology we have to mitigate those risks has also evolved. By conducting regular firewall testing, we can add strength to our network security and ensure a safe browsing experience.

Matthew is a freelance content writer whose work has previously appeared in well-known language-learning blog Fluent in 3 Months and The Happy Self-Publisher. His creative work has also appeared in Otoliths, CafeLit, and the Eunoia Review. He is currently based in Taipei, Taiwan, where he is studying for a master's degree in Chinese Literature.


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