The term Firewall comes from the bricks-and- mortar architectural world. In buildings, a firewall is a wall built from heat- or fire-resistant material such as concrete that is intended to slow the spread of fire through a structure. In the same way, a network firewall is intended to stop unauthorized traffic from traveling from one network to another.The most common deployment of firewalls occurs between a trusted network and an untrusted one, typically the Internet
1-Packet filtering routers : It’s implement set of rules in IP Packet and then it’s send this packet or discard it . 2- Application level gateway : it’s called proxy server and it’s work as application level traffic 3- Circuit level gateway : It’s works between an open systems Interconnection (OSI) network models transport and application layers such as the session layer
It’s work like filter between the computer and Internet. There are many different methods firewalls use to filter out information, and some are used in combination. These methods work at different layers of a network, which determines how specific the filtering options can be. If an incoming packet of information is flagged by the filters, it is not allowed through.
*Positive effects : User Authentication : Some firewalls can be set up to require users to user name and password ... This way you can control the type of services that the user can access them in addition to the possibility of tracking the activities of users
*Negative effects : Firewall crashes could disrupt the network full : In most cases, the firewall is the only point of connection between the internal network of reliable and extranet unreliable and thus disrupt the firewall or even in the case of incorrect settings will lead to a breakdown in communication between the two networks
Firewall Technical Impact : A firewall really important because malicious attacks What technology such as viruses that develop day after day Firewall social impact : There are people who enjoy to harm others, such as publishing bad programs such as viruses, Trojans and other and firewall came as barrier prevents these hackers and malware from access to users computers Thereby benefited society Firewall economic impact : When the firewall began running the first time companies competed later on production, thus affecting economically .
Legal outcomes of Firewalls : Contributed to the reduction of electronic issues . Technical outcomes of Firewalls : Helped to increase the safety of electronic devices and reduce the incidence of damage from hackers and viruses .