“Computer firewall” is software which is developed on the basis of operating system. It was mainly designed for control the access to unauthorized content on a computer. It works under some rules and instructions. According to those rules it decides whether to block or allow access.
Windows firewall is the firewall application used by many windows users. It acts quickly to the attacking Trojans and blocks the access to those networks. Access to the blocked networks is possible only when the setting of the application is changed.
This firewall technology was found in the 1980s, when internet itself had not reached the people widely. Routers were used to separate network accessibility and the demand for network security was not necessary.
The growth of the internet has brought in to the introduction of many firewall applications, each one having different features. Windows firewall is an application offered for free with the purchase of Windows OS.
Since the function of the firewall is based on the set of rules, it can often become worthless, if not configured properly. Optimized analysis has to be done on a computer followed by changes in the settings for complete protection.
Firewall is classified into three generation sets. These are classified manly because of their features and applications. A firewall program supports both on-line and off-line services. These firewall generation sets to control the installation and sharing of data files.
The first firewall is called as “packet filter”, which is mainly works for data transfer from the networks. The second generation firewall called as “stateful filter”. It’s main function to record the all set of connections passing through firewall and to determine the state of packets.
The third function is a proxy based application layer firewall. This detects the applications and protocols sneaking in, through the non standard ports. Harmful and abused protocols are also blocked.
Application layer-firewalls works on the application level of the TCP/IP stack. And it will intercept all packets traveling to or from an application. Firewalls are used to search unwanted outside traffic from computer. Firewalls will prevent outright the spread of worms and Trojans.