IT Simplified: What Is A Firewall?

Posted: 5th May 2021

In this new series of blogs, IT Simplified, we’re going to take a closer look at some of those terms that are often seen as ‘basic IT’ and therefore rarely explained. This week we’re asking what is a firewall?

Designed to protect your devices and servers from the threat of a cyber attack, a firewall is a software or network-based barrier that’s essential to your cyber security. See it as a guarded parameter that recognises authorised users and questions anyone else who tries to enter.

How does a firewall work?

Whilst unauthorised users are not permitted to pass the firewall, it doesn’t stop them from trying. So, as well as building a barrier around your systems, a firewall also watches and inspects all the data passing through. If something doesn’t sit right; signs of attack vectors or malicious code; it will be blocked.

Advanced firewalls can go a step further by making certain devices on your network untraceable, keeping a record of applications (good and potentially bad), and providing you with a list of potential risks that may need attention.

Types of firewall.

There are 5 types of firewall, each a graduation in the level of protection they provide:

Packet-filtering firewalls: A basic checkpoint for incoming traffic. This type of firewall will inspect surface-level information only such as the origin IP address, destination, and port number.

Circuit-level gateways: Another simple form of firewall which works by checking the data packet coming through is from a legitimate session. However, if the packet holds malware, it will pass through undetected.

Stateful inspection firewalls: These firewalls inspect where the data packet is coming from and its surface-level information. However, they can slow your systems down.

Proxy firewalls: A proxy firewall protects your systems by establishing a connection with the source of the traffic and thoroughly inspecting the contents before letting it through.

Next-gen (or UTM) firewalls: As the name suggests, a next-gen/UTM firewall does it all; inspecting the origin, surface-level information and data packet contents. Some may also include other technologies such as IPSs which automatically stop an attack on your network. The level of functionality can greatly vary so always check the capabilities before you invest.

Why is a firewall crucial to your cyber security strategy?

There are many ways a firewall can work to protect your business:

#1 Prevent remote access from unauthorised users looking to access your sensitive data. This could result in a ransom demand, significant downtime and even long-term damage to the reputation of your business.

#2 Act as a backup if essential software security updates are missed by bridging the gap that would otherwise be exploited by hackers.

#3 Continually watch for new threats in the form of trojans, viruses and other malware.

#4 Prevent email hijacking and consequent contact spamming from your business email accounts.

#5 Provide you with detailed reports on who is doing what on your network. Highlighting those users that are a potential data breach threat.  

#6 Provide a safe, secure connection for remote users.  

Jupiter IT – helping you make the right choices.

For some businesses, taking a pass on a firewall can be seen as an opportunity to save money. However, without a reliable one, you can fall victim to a serious and costly cyber attack.

If you’re feeling unsure about your cyber security strategy, we can help you understand your vulnerabilities and help you bridge the gaps with a free comprehensive IT audit. Just give us a call and speak to one of our qualified team.