What is a computer Network? A computer network is a system that uses communication tools and channels to connect several computer systems using unequal geographical locations & independent functions & realizes network hardware. Software and spread power origin and information transmission using a properly functioning network application. A system that connects two or more poly personal computers to communication.1. What is and what is a computer network?

The exact definition based on a personal computer network is not uniform.

Better definition of what a computer network is:

Computer networks consist primarily of several programmable hardware for mutually affiliated generic purposes that are not dedicated to an exclusive purpose (e.g., transmitting video signals for data completion). This programmable hardware can be used to transmit various types of data and can support an increasing number of implementations.

Some hardware: including computers, smartphones, smart sensors, etc.

Multiple implementations: including data, sounds, videos, and various applications that may exist in the future.2. What Is Computer Network Security And Threats Today

Computer Network Security is an act of using network management controls and technical measures to ensure that the confidentiality, integrity and usefulness of data in the network environment are protected.

And the threats that occur due to the factors below:

1. Threats of human error: human error operation, poor management, resulting in loss of system coverage, equipment theft, fire, flood, security loopholes left by imperfect security settings. Accidental user password leak. The settings make the user the right origin of the news power.

2. Threats to natural forces: e.g. earthquakes, storms, landslides, floods, lightning strikes, pests and rodent fauna, high temperatures and a great deal of pollution threats.

3. Intentional threats: Due to the vulnerability of the network itself, there are always some people or organizations that try to use the network system to achieve certain goals, such as “spies” involved in the collection of industrial, commercial or military intelligence.

Factors affecting the security of computer networks:

Companies create their own intranets to increase the speed of factual exchange and keep up with market demand. After establishment, the range of users will be expanded from company employees to customers & people who want to know the situation of the company. The increase in users also brings hidden dangers to network security.

When an intranet is created, the original local area network and stand-alone computers are interconnected, & host types are getting higher, e.g. workstations, servers, and even small computers & personal computers of grand & medium size. Because the operating system and network operating system they use are not the same, vulnerabilities in one operating system can result in great hidden dangers for the entire network.

Practice already illustrates that 80% of security cases are caused by internal networks. Therefore, the unit must attach great importance to the security of its own intranet and must formulate a set of rules and regulations for security management.3. Computer Network Functions

What is a computer network function? Especially on 3 aspects: sharing hardware power origin, spreading software resources & exchanging news between users.

(1) Sharing hardware resources. This can provide expensive tools such as processing power origin, storage power origin, & input and output resources on the entire network, as a result of which users can save on investment, and are also convenient for centralized management and balanced load sharing.

(two) Share application resources. Allows users on the Internet to access all types of Dalong databases from remote lag, they can obtain network archive transfer services, remote pause process management services, & remote archive access services, thus avoiding repetitive work in application development and storage of repetitive data power origins, & also convenient for centralization, management.

(three) News exchange between users. Computer networks provide a powerful means of communication for users spread across a wide variety of places. Users can send e-mails, publish news messages & perform e-commerce activities over a computer network.

An unaligned period has misaligned characteristics.

The first generation of computer networks is characterized by the information that the entire data processing and communication processing according to the host terminal system is completed by the host.

The second generation of personal computer networks are computers that have the ability to process data independently, but the level of spreading resources is not high.

The third generation of personal computer networks adopts a variety of protocols, & all personal computers on all networks follow the same protocol to realize resource sharing.

The 4th generation computer network proposes a digital network of broadband neutralization services, which is characterized by integration and high speed.

Basic characteristics of computer network communication:

2. Wide communication surface

4. Hyperlink mode that penetrates linear boundaries

five. Continuously improved interactivity

6. Flexible and changeable form of communication

The biggest feature is communication & network interactivity.4. Computer Network IP Address

Regarding personal computer networks, Labkom99 introduced the UDP protocol & TCP protocol network communication protocol in the previous article. And a brief introduction regarding the UDP protocol and the TCP protocol, this time Labkom99 will introduce what a computer’s personal network IP address is.

IP address: refers to the Internet Protocol Address, commonly known as IP. IP addresses are used to give unique numbers to personal devices of computers on the network. if we compare “personal computer exclusive” using “telephone”, then “IP address” is the same as using “phone number”.

IPv4: is a 32-bit binary sapta, generally divided as four bytes, expressed in abcd form such as 192.168.65.100. Among them, a, b, c, and d are all decimal integers between 0 and 255, so up to 4.two billion can be represented.

IPv6: Due to the development of the powerful Internet, the demand for IP addresses is getting higher, but the origin of network address power is limited, which makes IP allocation more tense. To expand the address space, it is proposed to define the return address space over IPv6, using a 128-bit address length, each group of 16 bytes, divided as 8 hordes of hexadecimal numbers, expressed into:

ABCD:EF01:2345:6789:ABD:EF01:2345:6789

It claims to be able to compile URLs for each piece of sand globally, as a result solving the problem of the origin of insufficient network address power.

To see the IP address of the machine, add it in the console: ipconfing

Check if the network is connected, enter on the console: ping space IP address, for example, ping 220.181.57.216

Local IP address: 127.0.0.1, localhost