All computers have thousands of ports that are used as communication paths between the PC's applications and services that are required on a network. Ports are like little open doors that allow two or more applications to talk to each other. Your computer has 65537 ports that may be used for various types of communication and data exchange. Of these, only 1025 are commonly used and designated as "well known ports". All software applications require the use of ports in order to work, but the majority of ports are not used for anything, creating a potential security risk if left open.
Quite often certain unneeded ports are left wide open by operating systems, browsers, and other installed applications, leaving secret back doors open on your computer. Most software developers frequently issue patches, service packs and hot fixes when they discover a security hole such as this, but many still go undetected. Software updates will close the open ports that the developer is aware of, which is why it's so important to perform regular computer updates.
Hackers and malicious software applications take advantage of open ports to infiltrate your computer. Spyware, viruses and other types of malware utilize open ports to retrieve information, destroy data and corrupt operating systems. Since unneeded open ports represent the "unlocked back doors" into your computer, it's important to prevent unauthorized access. A good way to see how vulnerable your computer is to outsiders is to do a port scan. Many security vendors offer an online port scan that will show you exactly how far into your computer a hacker can get. Once you learn what your PC's vulnerabilities are, you will see that it's time to get some protection.
A Firewall is the Best Defense
The best defense against the vulnerabilities associated with open ports is a good firewall. Firewalls act as a "guard" between your computer and the internet, allowing only authorized data in or out. Data packets that are not needed by you or your applications are blocked at the door, so they never get near you. Many firewalls also have a feature called "stealth mode", which makes your computer invisible to outsiders.
Software Firewall
For most home computer users, a software firewall (also known as a personal firewall) will provide sufficient protection. This type of firewall installs on your PC and is designed to protect your computer only. It is like having your own personal bodyguard. Some excellent firewall programs are made by internet security companies such as McAfee, Computer Associates, Zone Labs, Symantec, Sunbelt-Kerio, Trend Micro, and AVG - just to name a few. Software firewalls are the ideal security solution for laptop users who often access the internet from hotels, airports, coffee shops, etc…
Hardware Firewall
If you have a home network or business network, a hardware firewall is the best choice of protection. Hardware firewalls are security appliances that sit between your internet connection and the computers on your network. As opposed to protecting only one PC, a hardware firewall will protect all the computers on the network. Excellent hardware firewalls for business use are made by SonicWall, Barracuda, Hot Brick and Checkpoint, just to name a few. For home use consider D-Link, Linksys, or Alphashield.
It doesn't matter whether you use a hardware firewall or personal firewall, or even both. The main thing is that you do use a firewall to protect your computer from the vulnerabilities of open ports. Today's cyber-criminals are very sophisticated, and will take advantage of every security hole available. The best defense against this dangerous security issue is a firewall.
DJ is a corporate IT Manager and author of the following sites covering information technology topics: Computer Security for Everyone, http://www.saveonphoneservice.com, and http://www.antivirus-firewall-spyware.com
Article Source: http://EzineArticles.com/?expert=Debbie_Jacobsen
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