Is a firewall a system security technology?

Firewall is a system security technology.

The so-called firewall refers to a protective barrier composed of software and hardware devices and constructed on the boundary between the internal network and the external network, and between the private network and the public network.

A firewall is a technical measure to protect computer network security. It isolates internal and external networks by establishing a corresponding network communication monitoring system at the network boundary to block network intrusions from the outside.

Firewall technology was originally a protective measure taken against Internet network insecurity. As the name suggests, a firewall is an internal network barrier used to block the influence of external insecure factors. Its purpose is to prevent unauthorized access by external network users.

It is a combination of computer hardware and software that establishes a security gateway (Security Gateway) between the Internet and the Internet to protect the internal network from intrusion by illegal users. The firewall is mainly composed of service access policies It consists of four parts, verification tool, packet filtering and application gateway. A firewall is a piece of software or hardware located between a computer and the network it is connected to (hardware firewalls are rarely used and are only used by the Department of Defense and other places because of their price. expensive). All network traffic to and from this computer passes through this firewall.

From the perspective of implementation principles, firewall technology includes four major categories: network-level firewalls (also called packet filtering firewalls), application-level gateways, circuit-level gateways and rule inspection firewalls. Each of them has its own merits. Which one to use or whether to mix them depends on the specific needs.

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