Do I need a firewall?

Internet safety should always be at the top of your priorities – with technology ever-developing (and sometimes, not for the good), we have to be aware and we must protect ourselves.

Both incoming and outgoing internet traffic can be used to destroy files, cause malfunctions or copy your passwords. Internet Firewalls are an essential way to help protect you and your computer – correctly installed they put up a barrier between your home PC and internet threats.

When you use the internet information comes to your PC through various ports which are opened to receive certain types of data, e.g. web browsing or emails. A firewall is like the internet ‘bouncer’, it checks that the source’s address trying to connect to your computer through an open port is one you trust. Not using a firewall is taking a big risk.


If you’re currently using a home router, you’re already being protected. The router uses something called Network Address Translation (NAT) and shares just one IP address from your Internet Service Provider (even if you have multiple computers in the house). When any incoming traffic from the internet arrives at your router that you don’t trust, it doesn’t know which computer to send it to – and so it simply discards it. There are even some routers that allow you to block certain types of outgoing traffic.


This is a firewall that runs from your computer – it acts as a gatekeeper, allowing some traffic through but discarding incoming traffic. And the magic of software firewalls? They can monitor which applications want to use the Internet, block and/or allow traffic (on a per-application basis) – all because they run on your computer!


Now, you may be trying to choose the best for you – please remember that hardware and software firewalls do have some overlaps:

  • Unsolicited incoming traffic is blocked by default, by both – this means that any network services that may be vulnerable will be protected.
  • Certain types of outgoing traffic can be blocked by both – some routers don’t have this feature so be sure to check.
  • A hardware firewall is separate from your computer – for example, if your computer were to become infected with a virus, it could disable your software firewall. However, your hardware firewall would be unaffected by the virus and so would protect your computer.
  • Hardware firewalls can also provide network management that’s centralised. This means that if you run a large network, you can configure the settings of the firewall from one single device and don’t have to change it for each computer.


It’s vitally important for your online safety to use at least one type of firewall – hardware or software but whichever you choose provides you with unique benefits.

Remember, if you’re using a router and using the Windows firewall (Windows software firewall), you have some real security benefits with no excessive performance costs – therefore, it’s a great idea to run both.

It's fantastic to have proper high speed internet at last! John and the rest of the install team were great, please pass along my thanks.

- Andrew Green, Powys