What is a network protocol?
A network protocol is a set of rules used to specify data transmission and communication between communicating entities in a computer network. The network protocol covers various communication details, including packet format, error handling, data transmission rate, etc. It is a protocol for packet-switched data networks, and its task is only to transmit data according to the addresses of the source host and the destination host. Network protocols define addressing methods and encapsulation structures for datagrams. The first major version of the architecture was IPv4, which is still the widely used Internet protocol.
Network protocols are the rules for transmitting data on the network
Network protocols consist of a series of protocols. If you understand these protocols, you will understand the principles of the Internet. The network protocol defines the standards shared by everyone. We develop and use them according to the standards, which greatly improves our development efficiency and communication costs. Therefore, there are many protocols in each layer of the network, and the receiver and the sender are on the same layer. The protocols must be consistent, otherwise one party will not be able to recognize the information sent by the other party, and there is no way to enable various devices on the network to exchange information with each other.
For example:
A microcomputer user communicates with an operator of a mainframe in the network. Because the character sets used by the two data terminals are different, the commands entered by the operators do not know each other. In order to be able to communicate, it is stipulated that each terminal must first transform the characters in its own character set into characters in the standard character set before entering the network for transmission, and then transform them into characters in the terminal's character set after reaching the destination terminal. Of course, for incompatible terminals, in addition to changing the characters in the character set, other features also need to be converted, such as display format, line length, line number, screen scrolling method, etc., also need to be converted accordingly.
The composition of the network protocol
Network protocol is composed of three elements:
(1) Semantics.
Semantics is the interpretation of the meaning of each part of the control information. It specifies what kind of control information needs to be sent, as well as the completed action and what kind of response to make.
(2) Grammar.
Syntax is the structure and format of user data and control information, and the order in which data appears.
(3) Timing.
Timing is a detailed specification of the sequence in which events occur. (Also called "synchronization").
People vividly describe these three elements as: Semantics means what to do, grammar means how to do it, timing means the order of doing.
Commonly used computer network protocols
The three most commonly used communication protocols in the network are TCP/IP protocol, NetBEUI protocol and IPX/SPX protocol.
1) TCP/IP protocol
The TCP/IP protocol is undoubtedly the most important of these three protocols. As the basic protocol of the Internet, it is impossible for people to surf the Internet without it. Any operation related to the Internet is inseparable from the TCP/IP protocol. However, the TCP/IP protocol is also the most troublesome to configure among the three major protocols. It is okay to surf the Internet on a single computer. If you want to access the Internet through a LAN, you need to set parameters such as IP address, gateway, subnet mask, and DNS server in detail.
The TCP/IP protocol suite includes hundreds of interrelated protocols. Protocols with different functions are distributed in different protocol layers. Several commonly used protocols are as follows:
(1) Telnet (RemoteLogin): Provides remote login function, a computer user can log in to another remote computer, just like operating directly on the remote host.
(2) HTTP (HyperTextTransferProtocol): Hypertext Transfer Protocol is the most widely used network protocol on the Internet, and all WWW files must comply with this standard.
(3) FTP (FileTransferProtocol): A remote file transfer protocol that allows users to copy files from a remote host to their own computer.
(4) SMTP (SimpleMailTransferProtocol): Simple Postal Transfer Protocol, used to transmit email.
(5) UDP (UserDatagramProtocol): User Datagram Protocol, which is located in the transport layer like TCP and used in conjunction with the IP protocol. It saves the header when transmitting data, but it cannot provide retransmission of data packets, so it is suitable for short transmission document.
(6) NFS (Network File Server): A network file server that enables multiple computers to transparently access each other's directories.
2) NetBEUI protocol
Although the TCP/IP protocol is the most popular network protocol at present, the communication efficiency of the TCP/IP protocol in the local area network is not high. When using it to browse the computers in "My Network Places", the normal browsing phenomenon often occurs. Installing the NetBEUI protocol at this time will solve this problem.
NetBEUI is the abbreviation of "NetBiosEnhancedUserInterface", also known as NetBios Enhanced User Interface. It is an enhanced version of the NetBIOS protocol, which has been adopted by many operating systems. The NETBEUI protocol is useful in many situations and is the default protocol for operating systems before Windows98. The NetBEUI protocol is a short, compact, and highly efficient broadcast protocol. It does not need to be set up after installation, and it is especially suitable for transmitting data in "Network Neighborhood". Therefore, it is suggested that in addition to the TCP/IP protocol, the computers in the small LAN can also install the NetBEUI protocol.
3) IPX/SPX protocol
The IPX/SPX protocol was originally developed by Novell for NetWare networks, but it is also very commonly used. Most online games support the IPX/SPX protocol, such as StarCraft and Counter-Strike. Although these games can also be connected online through the TCP/IP protocol, it is obviously more convenient to use the IPX/SPX protocol because no settings are required at all. In addition, the IPX/SPX protocol does not seem to be very useful in non-local area networks. If you are not playing games online in the local area network, then this protocol is dispensable.
The Importance of Network Protocols in Network Security
Network protocols play a key role in network security, they ensure the safe transmission and proper processing of data. The following are several important aspects of network protocols in network security:
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Data encryption and authentication: Some protocols, such as HTTPS, use encryption technology during data transmission to protect data privacy. At the same time, the authentication mechanism ensures that the identities of both communication parties are legitimate.
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Prevent man-in-the-middle attacks: Network protocols can prevent man-in-the-middle attacks and ensure that the data between the two parties in the communication is not tampered with or stolen.
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Data Integrity: The protocol ensures that data is not damaged or tampered with during transmission and maintains data integrity.
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Access control: Some protocols implement access control, limiting which users can access specific resources.
Examples and Case Studies
Suppose a user visits a banking website while using a public Wi-Fi connection. Without proper network protocol protection, hackers may steal users' bank account information through snooping and man-in-the-middle attacks. But if the website uses the HTTPS protocol, the data will be encrypted to protect the privacy and security of users.
If it is a DNS hijacking attack, the attacker will guide users to malicious websites by tampering with DNS resolution results. The threat to network security from such attacks can be mitigated by implementing a hardened DNS protocol.
Network protocols play an integral role in network security, ensuring the secure transmission, authentication and proper processing of data. Understanding and applying appropriate network protocols is an important step in protecting personal privacy and information security.
I hope this article can help you better understand the definition, composition and importance of network protocols, as well as its key role in the network.
