Firewalls

Have you got a firewall on your computer? Which one is it? Do you know exactly how it works?

The term firewall originally referred to a wall intended to confine a fire within a line of adjacent buildings.

Firewalls can provide a range of services to help enforce a corporate security policy, including:

• intercepting and controlling traffic between networks – acting as a policy enforcement point between secure and unsecure networks.
• permitting configured applications – for example, allowing only web traffic and email to pass to the internal network.
• limiting the range of hosts that can send and receive traffic – for example, a firewall could be configured to prevent a specific server from connecting to the internet.
• limiting the types of data passing over the boundary – for example, preventing Java applets coming into the network.
• providing a centralised audit log of all outbound communications, auditing all connections to external destinations from users.