management information specification

14, a network protocol
Network protocol network (including the Internet) delivery, management information specification. As the interaction between people need to follow certain rules, mutual communication between your computer needs to abide by certain rules, and these rules referred to as the network protocol.A computer only comply with the network protocol, to other computers on the network normal communication. The network protocol is usually divided into several levels, each floor to complete their own separate function. Communicating parties only in the common level between can contact each other. C

15, network firewall
The concept of a firewall
The network firewall referred firewall, course, since intend Deep and to understand, we must first look at the concept of a firewall. The firewall is the name of a member of the automobile. In the car, use a firewall and the engine separated from the passengers, so that the car engine fire, the firewall is not only to protect the safety of passengers, while at the same time also allows the driver to continue to control the engine. Then computer terminology, of course, did not mean that we can analogy to understand, in the network, the so-called "firewall", refers to a separate intranets and public access network (eg, the Internet).

it is actually An isolation technology. The firewall is two networks communicate an access control measure, it can allow you to "agree" and data into your network, you "do not agree" and data out at the same time, maximize prevented network hacker to access your network. In other words, if you do not pass through the firewall, the people inside the company will not be able to access the Internet, people on the Internet can not communicate with people inside the company.The firewall should be able to reject all of the above types of attack packets and inform the firewall administrator.

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