Firewall ABC

The definition of a firewall
Referring to the so-called firewall is a software and hardware combination, intranet and extranet, private network and public network interface between the structure of barrier protection. Is a method of acquiring the image of security, It is a kind of computer hardware and software, so that the Internet and Intranet set up a secure gateway between the (Security Gateway), so as to protect the internal network from unauthorized users of the intrusion, firewall services from the main access rules, verification tools, including Gateway filtering and application of 4 parts, a firewall is located in the computer and connect its network between the hardware or software (which uses less hardware firewall, such as the Department of Defense, as well as large rooms and other places before, because it Expensive). The inflow and outflow of all the computer network were to go through the firewall.

The firewall function
It flows through the firewall on the network to scan, which can filter out some of the attacks, so that they will be executed on the target computer. Turn off the firewall can not use the port. But it can also prohibit the outflow of port-specific communications, blockade Trojan horse. Finally, it can be prohibited from special visit to the site in order to prevent intruders from unknown to all communications.