Today, computers need a firewall as much as they need anti-virus software. A firewall is a barrier to keep destructive forces away from your computer. A personal firewall is an application installed on your computer that controls network traffic to and from your computer, permitting or denying communications based on a security policy. Essentially, in order for information to cross the firewall, it must be approved by the firewall's set of rules.
If the information is not approved to enter, the firewall blocks it. This helps prevent external attacks from causing damage. Personal firewalls may also provide some level of intrusion detection, allowing the software to terminate or block connectivity where it suspects an intrusion is being attempted.
A personal firewall, along with anti-virus software and system patching, are vital parts of computer security and maintenance which every computer owner should understand and use.
When access to your computer is requested (e.g. downloading software or receiving emails), the firewall stops the transmission of information and asks for authorisation and/or verification from the user. The connection attempt will only be permitted if the security policy allows it, or if the user grants explicit permission.
Most Personal Firewalls require some training before they are fully configured. This is because they need to learn what programs you use and which ones connect to the internet. Personal Firewall’s generally pop up warnings when a program tries to connect to the Internet for the first time. The key thing is to pay attention to these messages and make sure that you only allow legitimate connections.
If the system has been compromised by Malware, Spyware or similar software, these programs can also manipulate the firewall, because both are running on the same system. It may be possible to bypass or even completely shut down software firewalls in such a manner. As a result, personal firewalls work hand in hand with antivirus programs.
The high number of alerts generated by such applications can possibly desensitise users to alerts by warning the user of actions that may not be malicious. Always pay attention to the messages produced by your firewall. If in doubt, choose the ‘deny’ or ‘block’ action.
A Personal Firewall should provide some of the folowing common features:
• Alert the user about unauthorised connection attempts and automatically block those connections.
• Allows the user to control which programs can and cannot access the Internet
• Hide the computer from the Internet by not responding to unsolicited network traffic
• Monitor and regulate all incoming and outgoing Internet traffic and prevent unwanted connections
• Provide the user with information about an application that makes a connection attempt
• A firewall should provide an activity log to alert the user of attempted intrusions.
• A Personal Firewall adequate for most users purposes is included for free with Windows XP and Windows Vista. It is turned on by default. You can replace it with a more sophisticated commercial desktop firewall or supplement it with a hardware firewall if you wish.
• Commercial grade Personal Firewalls often integrate well with other security products like anti-virus scanners.
• If you use a laptop, a Personal Firewall will protect you wherever you connect to the Internet.
• Never use two software firewalls at the same time. Completely uninstall one before installing another. Use the vendor's uninstall utility or if not available, use the Windows XP add/remove software tool in the control panel.
• You can use a hardware firewall including a Wired Router, Wireless Router or Broadband Gateway.
• Patches & Updates -- As soon as your firewall is installed, check the vendor's website for patches and updates. If the firewall offers an automatic update function, turn it on.
• Most importantly, pay attention to the messages and warnings generated by your firewall.