We recently spent a few days at Silverstone – not watching fast cars scorching around the race track, but installing firewalls.

There’s a lot of misconceptions about firewalls – I’ve even heard people saying that they don’t need them anymore, because the virus protection does the job.  It’s time to blow that myth out of the water.

There are two types of firewall, one is hardware and the other is software.  But what does a firewall really do?

Quite simply it blocks people from access, whether that’s access into your network from an external location, or access to files and folders internally.

Hardware firewalls

A firewall using hardware is installed on the perimeter of your network.  It allows access for certain things – such as your web server and email server – otherwise having computing power in your business would be redundant if you couldn’t receive email or get access to the internet!

Typically, a hardware firewall uses ports and these can be set to allow permissions, specific instructions for specific applications.  The challenge is to ensure everything is configured correctly so the right ports are pointing at the right thing, otherwise it doesn’t work.

Sometimes we have to turn firewalls off for testing purposes and to make sure things are working properly.  We have various equipment for testing and some of it would be blocked by a firewall, so after testing is completed we need to restore the firewall and ensure all the ports are still pointing in the right direction.

Software firewalls

If you’re operating on Microsoft Windows, there is a built in firewall – Windows Defender.  Mostly this works, but it doesn’t block everything.

Most anti-virus software has a firewall built in.  The paid versions are better, as they’re more robust and do a better job of protection.

Effectively a software firewall prevents access to your PC, and creates a barrier between your PC and the network or the internet.  This means that, if you’ve taken your laptop home and accidentally acquired any kind of malware, you can’t pass it on to your colleagues.

Your software firewall will protect your computer – and the rest of the network if a USB introduced by staff or external visitor has a sneaky virus on it (often totally unknown, even to the person who owns the USB).  Your software firewall leaps into action and scans for nasties before allowing access.

Back to Silverstone

The site we were working for already had a hardware firewall, but as with all things IT the manufacturers had discontinued it and were ending support, therefore to keep things current and within manufacturer support it was time for new hardware to be installed on the perimeter network.

We had to take into account that they have various networks including a VOIP telephone system, which runs through their broadband system.  That meant there were specific rule requirements to ensure telephone calls weren’t blocked by the perimeter firewall.

Their booking system is externally hosted, but has links to the internal servers, so that also had to be managed.  As with most clients they have a number of broadband networks, with a system that only staff can access, and a separate loop for guests and public access, which all had to be taken into account.

Firewalls can be programmed to prevent people from accessing certain websites by subject matter, there’s a comprehensive lists of subjects from social media networks through to information on weapons and war, not to mention naughty websites!

Every business and organisation is different, for instance in educational establishments the firewall needs to provide different access levels for tutors and students

Installing firewalls is like walking a tightrope so they’re open enough to work, but closed enough to protect your company.