Knowing More About Computer Firewalls
If you have been a computer and Internet user for a long period of time, then you may know a bit about firewalls or at least encountered the term. You may have even heard the oft used excuse that you couldn’t open a certain website because the firewall wouldn’t allow it. But what is a firewall and why is it important in keeping your computer secure?
What is a firewall?
Named just like the architectural firewall which is found in homes and other structures, a firewall is essentially a barrier that keeps your computer away from elements that could be destructive such as viruses and other infectious files. The physical firewall keeps fire from spreading from one house to another, and the computer firewall does the same kind of job – it protects your computer from getting viruses which might be transmitted by other computers in the same network as yours.
How do firewalls function?
Unlike the physical firewall, a computer’s firewall does allow certain elements to pass through to a computer although the firewall does filter all the information that it receives. If a certain packet of information is flagged by the firewall, then this data is not allowed the pass through.
Firewalls are extremely important to organizations which employ a network of a large number of computers. Let’s say that a company has a network consisting of 500 computers. These computers are all linked to each other. And on top of that, this network is also connected to the Internet. Without any firewall, a person can easily probe into this network, disrupt operations and even steal information since access to the network and the computer isn’t as strict as it would be if firewalls were employed.
There are three ways that firewalls are able to regulate the flow of information into certain computers:
Packet filtering. Packets, or small clusters of data, are analysed with the help of certain filters. If a packet is cleared by the filter, then it is allowed to go through to the requesting computer but if it was flagged then it would be discarded.
Proxy service. The firewall is responsible for retrieving information found in the Internet and then this packet of information is sent to the requesting system. This filtering method also works the other way around wherein information is sent from a computer with a firewall to a network.
Stateful Inspection. This newly introduced method of filtering information works by comparing specific parts of a packet of information to a trusted database. If the comparison if favorable, then the packet is allowed to go through.
The writer, Keith Daniels, loves to blog about websites, servers and social media campaigns. He shares great insights about Macquarie Telecom Ltd