A firewall protects your organisation against:
What a firewall does NOT do:
A firewall is not sufficient on its own to guarantee security, but constitutes the first line of defence. You also need to take the other protective steps outlined on this website. Remember that a firewall provides little or no protection against the following:
However, none of above constitute a reason NOT to install a firewall, as you should always assume that your ISP does NOT provide any kind of firewall.
Types of firewall
Personal firewalls should be installed on each computer that is connected to the internet and monitors (and blocks, where necessary) internet traffic. They are also sometimes known as ‘software firewalls’ or ‘desktop firewalls’.
Windows Firewall is a basic personal firewall. It is free, included with Windows operating systems. In Windows 8, Windows 7 and Vista, the Firewall defaults to active, so you need not worry about configuring it yourself.
If you wish, you could replace Windows Firewall with another personal firewall of your choice, including the type incorporated in some internet security packages, or standalone firewall software which can be downloaded from the internet, some of which is free of charge.
Medium-sized and large businesses may need a hardware firewall – in addition to personal firewalls – depending on the configuration of your IT infrastructure. If in doubt, seek professional advice on selection installation and configuration of the most suitable one for your business needs.
Check if your Windows Firewall is switched on in your computer's System and Security settings in the Control Panel