We know that Internet is a way of quick communication, business, various types of information and entertainment. Its use increased day by day. It had bed impact like others – it spread virus, spam, spyware etc. A personal computer connected to the internet without a firewall can be hijacked and added to an internet outlaw’s botnet in just a few minutes.
What is Firewall?
A firewall is a dedicated appliance, or software running on another computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules. A firewall is an integrated collection of security measures designed to prevent unauthorized electronic access to a networked computer system. It is also a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all computer traffic between different security domains based upon a set of rules and other criteria. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
There are several types of firewall techniques:
Packet filter: Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.
Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.
A firewall can block malware that could otherwise scan your computer for vulnerabilities and then try to break in at a weak point. The only way to make a home computer 100% secure is to turn it off or disconnect it from the Internet. The real issue is how to make one 99.9% secure when it is connected. At a minimum, home computers need to have personal firewall and anti-malware software installed and kept up-to-date to find and remove viruses, spyware, Trojans and other malware. A home network that uses a wired or wireless router with firewall features provides additional protection.
Personal Firewall Cooices:
Microsoft Windows Firewall — The Vista and XP Service Pack 2 operating systems have personal firewalls built in that are turned on by default to block threats from the Internet. You should leave this feature turned on until you replace it with third-party software and/or hardware.
Two-Way Third-Party Personal Firewall Software — These firewalls block both incoming and outgoing threats. A computer has outgoing threats when it becomes infected with a virus, trojan horse or spyware. A challenge for this type of firewall is to distinguish between threats and legitimate software. Three common ways to address this are by vendors including a list of safe software for the firewall to check [white list], malware to block [black list] and/or by issuing a pop up alert to the user asking for advice on what to do [better for experts]. For links to vendors and reviews of over fifty products, see our Personal Firewall Reviews page. Recommended products with links to vendors:
nternet Security Software Suites — These products include two or more security features such as a personal firewall, anti-virus, anti-spyware and more. For links to vendors and reviews of over 20 products, see our Internet Security & Utility Suites page. Recommended retail products with links to vendors:
Hardware Firewalls — A hardware firewall is usually a small box that sits between a modem and a computer or network. The firewall is either based on “network address translation” (NAT) which hides your computer from the Internet or NAT plus “stateful packet inspection” (SPI) for more protection. There are three basic types of hardware devices that include firewalls for home users, Wired Routers, Wireless Routers, and Broadband Gateways. They are inexpensive enough to be used with one computer and can also be used to create a home computer network. They can be used in addition to a software firewall on each computer because they run on a separate box preventing most compatibility problems. Recommended broadband gateway retail products with links to vendors.
Important Tips — Never use two personal firewall software products at the same time. Fully uninstall one before installing another to prevent compatibility problems. After installation, be sure to test it with an online service like Security Space to make sure that it is configured correctly.