An Introduction To Firewalls
Network firewalls are an important resource for any computer. They work to control and monitor data access from both sides, the Internet and the computer. Computer firewalls take their name from real life firewalls which prevent fires from spreading.
While there are two types of firewall, hardware and software, however some type of software needs to go with the hardware version and of course software needs some type of hardware to reside on.
Hardware firewalls are most typically used between networks. One example of this may be between a corporate network and the Internet. Most administrators set up firewalls so that incoming Internet traffic may be sent to a specific computer or public access area whereas computers within the networks can access the Internet directly. Internal firewalls are also often used which can restrict access for certain user or groups as well as prevent the spread of computer viruses.
Software firewalls are typically used at home on personal computers for secured Internet access. Software firewalls do use computer resources and are typically slower than hardware firewalls. However, for personal Internet use a hardware firewall is quite unnecessary.
Firewalls work by forcing all outgoing and incoming network and Internet traffic to follow a policy. A policy is simply a set of rules which programs and data packets must follow.
Many types of programs require access to the Internet and therefore must be allowed in the firewall’s policy. Internet browsers, email programs, and auto-updating programs such as anti-virus software are just some examples of these types of applications.
More firewalls work by altering you the first time a program tries to access the Internet. If you want to allow access you can configure your firewall as such. Typically if you don’t recognize the program trying to access the Internet disallows it in the policy.
Another important function of the firewall is to close unnecessary ports which are access points from your computer to the Internet. Hackers can find these ports and use them to transfer worms and gain access to your computer. Firewalls can help prevent this from happening. Many firewalls not only close these ports but also render them invisible, making an attack virtually impossible.
The downside to software firewalls is that they are just that, another piece of software which makes them vulnerable to viruses just as any other program installed on your computer. Because of this you should always use common sense when accessing the Internet, never rely solely on your firewall.
[tags]firewall,internet security,privacy,hackers[/tags]
