Firewalls are an extremely beneficial and necessary security tool that organizations need to implement in their network. There are so many ways that information can be shared over the internet either by an organization's employee for example just searching on the net or by hackers trying to break into the network. Thus, organizations need to implement a security device such as a firewall to protect them from the world (internet).
A firewall is a security device that acts as a barrier between two networks, i.e. an organization and the internet. There are two types of firewalls, either hardware or software. Firewalls are built into routers and you can also get software such as Zone Alarm which is software that acts as a firewall.
A firewall, working closely with a router program, examines each network packet to determine whether to forward it toward its destination. A firewall also includes or works with a proxy server that makes network requests on behalf of workstation users. A firewall is often installed in a specially designated computer separate from the rest of the network so that no incoming request can get directly at private network resources. "Firewalls use one or more of three methods to control traffic flowing in and out of the network:
Packet filtering - Packets (small chunks of data) are analyzed against a set of filters. Packets that make it through the filters are sent to the requesting system and all others are discarded.
Proxy service - Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa.
Stateful inspection - A newer method that doesn't examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information. Information traveling from inside the firewall to the outside is monitored for specific defining characteristics, then incoming information is compared to these characteristics. If the comparison yields a...
References: How firewalls Work. Retrieved February 14, 2007, from www.howstuffworks.com.
Firewall. Retrieved February 14, 2007, from www.whatis.com.
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