Firewall is essentially a filter. It is either a software program or hardware device used in computer systems to prohibit forbidden information for passing though, while allowing approved information. The communication which the firewall prevents from passing though could be hackers trying to gain access to your personal information stored on your computer.
The firewall inspects all the information which is passed over the system and determines if it is a threat or not based upon a variety of factors. It then stops all potential threats from passing through. The criteria which a firewall uses to determine whether or not information in a threat or not is carefully determined.
Firewalls are important for anyone with online security concerns. Firewalls can be used for businesses, known as a corporate firewall or by individuals, known as a personal firewall. It has long been known the firewalls are a necessity for businesses to protect their networks; however, the demand for personal firewalls has increased dramatically.
There are two types of firewalls the Hardware Firewall and the Software Firewall. A Software Firewall is a software program and a Hardware Firewall is a piece of hardware. Both have the same objective of filtering communications over a system. Systems can use a Hardware Firewall, a Software Firewall, or a combination of both.]]>
If you computers ports are open to the internet than you need firewall protection. That means, if your internet is always connected for instance cable internet or DSL, or if you use dial up for extended periods of time, you should protect your computer with a firewall.
The internet is full or individuals that are waiting for any signs vulnerability, looking to take advantage of holes in your computer's security. Whether they are looking to steal your private information, or damage your computer system, it is the firewall's job to make sure they are denied access. The firewall acts as your system's bouncer, making sure anyone you want to let in can pass without delay while stopping all the other creeps at the door or in this case port.
A proxy is either a router or a computer system that creates a break in the link from the sender and receiver. All requests which are sent between the client and the server are processed through the proxy. There is no longer a direct connection between the client and internet as all requests are fielded by the proxy and the proxy can refuse access to any unauthorized communications.
One technique firewalls use is a Proxy Server; this catches all communication, in both directions. Another technique is Packet Filtering which checks all packets going through a network and determines whether is allowed by specifications determined by the user. Firewalls can also use an Application Gateway or a Circuit Level Gateway.
Port 80 is the default port which HTTP transactions (web transactions) pass through.]]>
What are the most important points to focus on when choosing a firewall?
If you would like to check if your firewall is functioning properly you can run what is called a port scan which will check if a connection to any of your system's ports can be established. If so your firewall is not doing what it should be.]]>
Packet filtering firewalls are generally a part of a router and work by filtering the packet which the router receives. When the router receives the packet from a network the firewall checks it according to specific list of rules and decides whether or not to forward it to the next network.
Circuit level gateways do not filter each packet but rather check that each session is secure. They work at the session layer of the OSI model and inspect the TCP handshaking between packets. If a session is deemed secure then a connection is made.
Application level gateways, otherwise known as proxies, filter packets from the application layer of the OSI model. Filtering at the application layer enables them to differentiate between different application commands.
Stateful multilayer inspection firewalls are the most complex of firewalls. They are essentially an amalgamation of the other three types of firewalls. They first evaluate packets at the network level, they then check if the packets are allowed and inspect the packets contents at the application level.]]>