How to quickly learn about network protocols and network protocols

How to quickly learn about network protocols and network protocols
I. What is the network protocol?

Generally speaking, network protocols are a bridge between networks for communication and communication. Only computers with the same network protocol can communicate and communicate information. This is like the various languages used for communication between people. Only when the same language is used CAN communication be conducted normally and smoothly. From a professional perspective, network protocols are the protocols that computers must abide by when implementing communications in the network. It mainly sets out the information transmission rate, transmission code, code structure, transmission control steps, error control, and other standards.

Ii. network protocol selection

We may have no choice over many network protocols. However, if you know the main purpose of the network protocol in advance, you can make targeted choices. The following are common network protocols:

NetBEUI (NetBIOS Enhanced UserInterface) Network Basic Input/Output System extended user interface

The NetBEUI protocol was proposed by IBM in 1985. NetBEUI is mainly designed For a LAN of 20 to 200 workstations. It is used For NetBEUI, LanMan, Windows For WorkgroUPS, and Windows NT networks. NetBEUI is a compact and fast Protocol. However, because NetBEUI does not have the routing capability, it cannot route from one LAN to another, and can no longer adapt to a large network. To route to another Lan, you must install TCP/IP or IPX/SPX.

IPX/SPX (Internetwork Packet Exchange/Sequential PacketExchange)

It is a network protocol proposed by Novell for client/server connection. The IPX/SPX protocol can be used to run programs that usually require NetBEUI support. The IPX/SPX protocol can be used to access other networks through routers.

High-Level Data Link Control (HDLC) High-Level Data Link Protocol

It is a set of protocols used to transmit data between network nodes. In HDLC, data is sent over a network in units (frames) and confirmed by the receiver. The HDLC Protocol also manages the interval between data streams and data transmission. HDLC is one of the most widely used protocols in the data link layer. As an ISO standard, HDLC is based on the ibm sdlc protocol, and SDLC is widely used in IBM mainframe environments. In HDLC, SDLC is called the call response mode (NRM ). In normal response mode, the base station (usually the mainframe) sends data to a local or remote second-level Station. Different types of HDLC are used for networks using the X.25 protocol and Frame Relay Network, which can be used in LAN or wide area networks, whether public or private.

HTTP1.1 (Hypertext Transfer Protocol Vertion 1.1) Hypertext Transfer Protocol-Version 1.1

It is a transfer protocol used to transmit hypertext on the Internet. It is an HTTP application protocol running on the TCP/IP protocol family. It can make the browser more efficient and reduce network transmission. In addition to HTML files, any server also has an HTTP resident program to respond to user requests. Your browser is an HTTP client and sends a request to the server. When a starting file is entered in the browser or a hyperlink is clicked, the browser sends an HTTP request to the server, this request is sent to the URL specified by the IP address. The resident program receives the request and sends the requested file back after necessary operations.

HTTPS (Secure Hypertext Transfer Protocol) Secure Hypertext Transfer Protocol

It is developed by Netscape and built in its browser. It is used to compress and decompress data and return the results of network upload and return. HTTPS actually uses Netscape's full Socket Layer (SSL) as the child layer of the HTTP application layer. (HTTPS uses port 443 instead of using port 80 as HTTP to communicate with TCP/IP .) SSL uses 40-bit keywords as the RC4 stream encryption algorithm, which is suitable for business information encryption. HTTPS and SSL support X.509 digital authentication. If necessary, you can confirm who the sender is.

ICMP (Internet Control Message Protocol) Internet Control Information Protocol

It is a message control and error reporting protocol between the host and the gateway. ICMP uses IP datagram, but messages are processed by TCP/IP software, which is invisible to application users. In a system called Catenet, the IP protocol is used as the datagram service from the host to the host. A network connection device is called a gateway. These gateways exchange information for control through the gateway-to-Gateway Protocol (GGP. In general, the support or target host will communicate with the source host, for example, to report errors during the datagram process. For this purpose, ICMP is used. It uses IP addresses for underlying support, as if it is a high-level protocol. In fact, it is part of the IP address and must be implemented by other IP modules. ICMP messages are sent in the following situations: when the datagram cannot reach the destination, when the gateway has lost the cache function, when the gateway can direct the host to send on a shorter route. The IP address is not designed to be absolutely reliable. The Protocol aims to return control information when a network problem occurs, rather than making the IP protocol absolutely reliable, it is not guaranteed that data packets or control information can be returned. Some data packets will still be lost without any report.

IMAP4 (Internet Mail Access Protocol Version 4) Internet Mail Access Protocol-Version 4

It is a standard protocol used to access email from a local server. It is a C/S model protocol, and the user's email is received and saved by the server. IMAP4 improves POP3. You can browse the mail header to determine whether to download the mail, and create or change folders or mailboxes on the server, delete a letter or retrieve a specific part of a letter. When a user accesses an email, IMAP4 needs to continuously access the server. In POP3, the mail is saved on the server. When the user reads the mail, all the content will be immediately downloaded to the user's machine. We can sometimes regard IMAP4 as a remote file server and POP3 as a storage and forwarding service.

NNTP (Network News Transfer Protocol) Network News transmission Protocol

Like POP3, NNTP also has some limitations.

IOTP (Internet Open Trading Protocol) Internet Open Trade Protocol

Internet open trade agreements are a series of standards that make electronic purchase transactions consistent among customers, sellers and other related parts, regardless of the payment system used. IOTP is applicable to many payment systems, such as SET, DigiCash, electronic check or debit card. The data in the payment system is encapsulated in the IOTP message. Transactions processed by IOTP can include customers, sellers, credit check, certificates, and banks. IOTP uses the XML Language (Extensible Markup Language) to define data contained in transactions.

IPv6 (Internet Protocol Version 6) Internet Protocol-Version 6

It is the latest version of the Internet Protocol and has been supported by many major operating systems as part of the IP address. IPv6, also known as "Ipng" (next-generation IP address), implements major improvements to the current IP address (version 4. You can use IPv4 and IPv6 network hosts and intermediate nodes to process any layer of packets in the IP protocol. Users and service providers can directly install IPv6 without making any major changes to the system. Compared with version 4, the biggest improvement of the new version is to change the IP address from 32-bit to 128-bit. This improvement aims to meet the needs of the rapid development of the network for IP addresses, it also fundamentally changes the problem of IP address shortage. This simplifies the deletion of IPv4 header fields or becomes an optional field, which reduces the overhead of packet processing and the bandwidth occupied by IPv6 headers. Improved IP header option encoding, resulting in more efficient transmission, fewer restrictions on option length, and stronger adaptability when new options are introduced in the future. Add a new capability so that packages of special transmission streams that the sender requires special processing can be tagged, such as non-default quality services or real-time services. To support authentication, data integrity and (optional) Data Confidentiality extensions are described in IPv6. This article describes the basic IPv6 Header and the IPv6 extension header and options that were initially defined. We will also discuss the packet size, the syntax of data stream labels and transmission classes, and the impact of IPv6 on upper-layer protocols. The format and syntax of IPv6 addresses are described separately in other articles. IPv6. all IPv6 applications must contain ICMP.

MIME (Multi-Purpose Internet Mail Extensions) Multi-Function Internet Mail Extension

MIME is an extended SMTP protocol, which was proposed by Nathan Borenstein to IETF in 1991. While transmitting character data, users are allowed to transmit additional file types, such as sound, images, and applications, and compress them into MIME attachments. Therefore, the new file type is also used as the new supported IP file type.