A firewall is a part of a computer system or network that prevents unauthorized access to the system while allowing access to authorized computers. There are three types of firewalls: the network-level firewall, the circuit-level firewall, and the application-layer firewall.
A network-level firewall inspects packet headers and filters traffic based on the IP address of the source and destination. It will not allow packets to pass through it unless they match the rule set that is either established by default or defined by the network administrator. It works under the ...
The expert describes the three main types of firewalls. How each type protects a network is explained.