What is a firewall?

When it comes to computer tech-speak, the term ‘firewall’ is old-school – it was first applied to computer technology in the early 1990s. And when a word has been kicking around for some thirty years, we’re pretty much all familiar with it. But do we all understand what it means? What exactly is a firewall?

Defining a firewall

In building construction, a firewall is used to protect one part of a building from a fire in another. Using this as an analogy, a computer firewall is used to protect one (trusted) part of a computer network – generally your home computer or your business network – from another (less-trusted) part – ie the internet or a wide area network (WAN) such as across a university or across government departments. The firewall – either a piece or software (or hardware, in the form of an external unit) – filters all network traffic between the ‘inside’ (safe) and the ‘outside’ (likely not safe!).

So what does the firewall do (and not do)?

The job of a firewall is to enforce rules about what network traffic can enter or leave your personal computer or company network. Generally the rules are designed to let the ‘good’ traffic through (that important email you’ve been waiting for! that video of dogs home alone you’ve been told about!), while keeping the ‘bad’ traffic out (hackers! malware!). A large part of setting up a firewall can be configuring these rules. For a personal computer this may be relatively straightforward, but setting up the rules for a larger business, with a number of servers, users and/or departments, can be far more complicated.

Most firewalls also include a reporting mechanism of some kind – logging external and internal network attempts to penetrate the system.

This all sounds great, of course, but it’s important to remember that a firewall cannot scan the system for malware or perform actions with virus-infected files. Various anti-viruses are used for these purposes. And it is very important to remember that the firewall cannot protect your computer or network from computer viruses that come from infected media – an infected program on a USB flash drive, for example.

What now?

A firewall, if implemented correctly, can essentially make your computer or business network invisible to the ‘internet bad guys’. So:

  • Ensure your firewall is up and running (check in Control Panel/Security in Windows or System Preferences/Security on a Mac). Get in touch if you have any questions!
  • If you’re shopping for a firewall to protect your computers and the information on them, you want the firewall software and/or hardware to be effective and appropriate for your requirements. Talk to us about a system tailored to your needs – our certified IT specialists can walk you through the options and partner your business going forward with IT support and managed server solutions.

With decades of IT experience – yep, we were there in those early days of the firewall! – our local team at Geelong Technology Group are here to answer your questions and to take your business to the next level (safely and securely). We are conveniently located in Belmont, Geelong, and we also offer on-site support to the Greater Geelong, Bellarine Peninsula, Surf Coast and surrounding regions, or remote support if you’re further afield. Contact our experienced IT technicians on (03) 5244 3030 or email for quality advice about your personal or business computing needs.


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