What is a Firewall

While networks offer great advantages with sharing data and resources, they are also a major weakness in maintain the security of data and software.

A firewall is a special type of software or hardware that ‘plugs up’ all of the security holes and makes it very difficult for hackers to gain access to your network. Firewalls are essential for any LAN connected to the Internet, as they help reduce the vulnerability of your network to hacker attacks.

Firewalls work by analysing all the data traffic going in and out of a network. When traffic does not meet certain rules for ‘allowed traffic’, the traffic is stopped and the transfer of data is denied. A network administrator will initially set up the firewall rules to allow traffic such as email, web site browsing and other forms of data transfer to occur. This allows firewalls to be set up to not only stop hackers but also stop people connected to the LAN from accessing outside information they should not be looking at (such as web sites with adult content or online gaming).

Logging features are included in most firewall solutions to enable the LAN administrator to analyse information about firewall security violations. This information is invaluable when a security attack occurs, and may be used to track and prosecute offenders.

Typically, a small network will use a cost effective software firewall whereas larger networks (such as a corporate network) will use a more expensive hardware firewall.


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