Network protocol specifications (part I)

Network protocol specifications (part I)
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Www.net130.com Date: 2005-12-11
Author: Wang hanhui Source: IT expert network

There are many protocols in each layer of the network, which define the communication rules through the network. the sender of the receiver must be consistent with the Protocol at the same layer. Otherwise, one party will not be able to identify the information sent by the other party, this rule requires both parties to complete the transfer of information between computers. The following describes the network protocol specifications.

ARP (Address Resolution Protocol) Address Resolution Protocol

It is used for ing computing.

Host physical address and temporary network address. At startup, it selects a protocol (Network Layer) Address and checks whether the address has been used by another computer. If it is not used, this node is used, if this address has been used by another computer, the computer that is using this address will advertise this information and only select another address.

SNMP (Simple Network Management p) Network Management Protocol

As a part of TCP/IP protocol, it provides a standardized approach for local and remote network device management and is an important part of centralized management in a distributed environment.

Appleshare protocol (appleshare Protocol)

It is the communication protocol on apple. It allows computers to request services from servers or exchange files with servers. Appleshare can work on TCP/IP or other network protocols such as IPX and appletalk. When using it, users can access resources on files, applications, printers, and other remote servers. It can communicate with any server configured with the appleshare protocol. Macintosh, Mac OS, Windows NT, and Novell Netware support the appleshare protocol.

Appletalk Protocol

It is the main network protocol used by Macintosh computers. The Windows NT Server is dedicated to the Macintosh Service and supports this protocol. It allows Macintosh users to share Mac-format files stored in the Windows NT folder, or use a printer connected to Windows NT. Windows NT shared folders appear in front of Mac users in the form of traditional Mac folders. Mac file names are converted to the fat (8.3) format and NTFS file standards as needed. Supports Mac file format DOS and Windows clients to share these files with Mac users.

Bgp4 (Border Gateway Protocol vertion 4) Border Gateway Protocol-version 4

It is a protocol used to exchange route information between gateway hosts (each host has its own route) in an autonomous network. It enables administrators to configure route weighting on known routing policies, CIDR is a mechanism that can accommodate more addresses in the network. It is updated than the external Gateway Protocol (EGP. Bgp4 is often used between gateway hosts. The route table in the host includes the list of known routes, accessible addresses, and route weighting, so that you can select the best path in the route. BGP uses the internal BGP (ibgp) for communication in the LAN, because ibgp cannot work very well.

BOOTP protocol

It is a TCP/IP-based protocol that allows diskless sites to obtain IP addresses from a central server. Now we usually use DHCP protocol to do this.

CMIP (Common Management Information Protocol) Common Management Information Protocol

It is a network management protocol established in the Open System Interconnection and communication mode. Related Common Management Information Service (CMIS) defines methods for receiving status information from network objects, devices, and devices.

Connection-oriented protocol/connectionless protocol

The protocol used by the two computers to establish a physical connection in the Wide Area Network. This physical connection continues until data is successfully exchanged. In the Internet, TCP (Transport Control Protocol) is the protocol of this type, it provides two computers connected to the network with a means to communicate with each other and ensure successful data transmission. Connection-oriented protocols must ensure that data is transmitted to the other party. In the wide area network, protocols that allow the recipient's computers to transmit data from one computer to another without going online or testing the reception capability. This is the main protocol in the packet switching network. The IP protocol in the Internet is no connection protocol. IP addresses only focus on dividing data into data packets for transmission, and regroup packets after these packets are received, do not focus on the status of the recipient's computer. The connection-oriented protocol (such as TCP in the internet) ensures data receipt.

Dynamic Host Configuration Protocol (DHCP)

It is a protocol that enables clients to obtain configuration information on TCP/IP networks. It is based on the BOOTP protocol and adds functions such as automatic allocation of available network addresses based on The BOOTP protocol. These two protocols can interwork through some mechanisms. When installing the TCP/IP protocol and using the TCP/IP protocol for fast connection, DHCP must be configured with three parameters: IP address, subnet mask, and default gateway, you can also use DHCP for automatic configuration.

Discard protocol discard Protocol

It is used to debug the network status. TCP-based discard service. If the server implements the discard protocol, the server detects the discard Protocol Request on TCP port 9. After the connection is established and the request is detected, directly discard the received data until the user interrupts the connection. The discard service based on UDP protocol is similar to TCP, and the detection port is UDP port 9, and the function is the same.

Echo protocol Protocol

This Protocol is mainly used for debugging and testing. The role of this protocol is also very simple, and it is enough to receive the original mails sent back. Based on the TCP protocol, the server can check for messages on TCP port 7. If a message is sent, the server returns the message directly. If the basic process of using UDP protocol is the same as that of TCP, the detected port is also 7.

File Transfer Protocol (FTP)

It is a standard protocol and the easiest way to exchange files between computers and networks. FTP is also an application protocol standard that applies the TCP/IP protocol, just like the HTTP and SMTP of the e-mail that delivers the display file. FTP is usually used to upload a webpage from the Creator to the server for use, while uploading and downloading files from the server is also very common. As a user, you can use ftp on a very simple dos interface, or update (delete, rename, move, and copy) using FTP on a graphical interface provided by a third party) files on the server. Currently, many servers support Anonymous logon, allowing users to log on using FTP and anonymous as user names. Generally, you can use any password or press the Enter key only.

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.

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.

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.

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.

Open Shortest Path First (OSPF)

OSPF is a protocol standard used to replace routing information protocols in large autonomous networks. Like rip, OSPF is designed by IETF as a standard in the internal gateway protocol family. When OSPF is used, changes in the network topology can be immediately reflected on the vro. Unlike rip, OSPF is not the route table saved by all current nodes, but is calculated using the shortest-out priority algorithm to reduce network traffic. If you are familiar with the most short-circuit priority algorithm, you will know that it is an algorithm that only cares about the network topology, rather than other situations, such as priority, OSPF changes the algorithm so that it gives priority to certain paths based on different situations.

POP3 (Post Office Protocol Version 3) Post Office Protocol-Version 3

It is a client/server protocol for receiving emails. The email is received and saved by the server. after a certain period of time, the client's email receiving program checks the mailbox and downloads the email. POP3 is built in IE and Netscape browsers. Another alternative protocol is the interactive mail access protocol (IMAP ). With IMAP, you can treat emails on the server as emails on the local client. Emails deleted on the local machine can also be found on the server. E-Mail can be saved on the server and retrieved from the server.

Point-to-Point Protocol (PPP)

It is the communication protocol between two computers used for serial interfaces. It is a protocol for communication between computers and servers through telephone lines. Network service providers can provide you with point-to-point connections, so that the provider's server can respond to your requests, receive and send your requests to the network, and then send the responses to the network. PPP is a member of the TCP/IP protocol family. The PPP protocol can be used for full duplex protocols for different media, including twisted pair wires, optical fiber cables, and satellite transmission. It uses HDLC for package loading. The PPP protocol can both process synchronous communication and asynchronous communication. It allows multiple users to share a line and control errors not implemented by the slip protocol.

Rip (routing infomation protocol) routing information protocol

Rip is one of the earliest routing protocols and is still widely used. It should belong to the Internal Gateway Protocol (IGP) class, which is a distance vector routing protocol. This protocol calculates the distance between two locations and only the number of routers passing through, if there are two vrouters with different speeds or bandwidths to the same destination, but the number of routers passing through is the same, rip considers the distance between the two as the same, and when actually transmitting data, obviously, the speed is slow, which is the disadvantage of the RIP Protocol, and OSPF overcomes the shortcomings of rip.

Slip (Serial Line Internet Protocol) Serial Line Internet Protocol

It is a TCP/IP protocol used for communication between two computers. Generally, the line connecting a computer to a server is a serial line, rather than a T1 line or a parallel line. Your server provider can provide you with a slip connection so that your server can respond to your request, send the request to the network, and then send the results returned by the network to your computer. Now it is gradually replaced by PPP Point-to-Point Protocol with better functions.

SMB protocol (Server Message Block protocol) server information block Protocol

It provides a method for a program running on a client computer to request server services on the network. It can be used over TCP/IP or over network protocols such as IPX and netbeui. When using the SMB protocol, applications can access resources on remote computers, including printers and named pipelines. Therefore, a user program can read, create, and update files on a remote server, or communicate with a computer that has installed the SMB protocol. Microsoft Windows for workgroups, Windows 95, and Windows NT both provide support for SMB protocol clients and servers. For Unix systems, the shared software Samba also provides similar services.

LMTP (Local Mail Transfer Protocol) Local mail Transmission Protocol

SMTP and SMTP service extensions (ESMTP) provide an efficient and secure method for sending emails. To implement SMTP, you need to manage a mail transfer queue, in some cases, this may be troublesome and requires a mail delivery system without a queue. LMTP is such a system. It uses ESMTP syntax, and it is not the same as ESMTP, LMTP cannot be used for TCP port 25. LMTP is very similar to SMTP and ESMTP. To avoid confusion with SMTP and ESMTP services, LMTP uses the lhlo command to start an LMTP session. Its basic syntax is the same as that of Helo and EHLO commands. For the data command, if the RCPT command fails, the Data command must return 503 and fail. Each Data command Encounters ". "the server must return a response to all successful RCPT commands, which is different from the normal SMTP system and must be in the same order as the successful RCPT command, even if there are many RCPT commands in the same forward path, multiple successful responses must be returned. This means that the server returns a confirmation response that means the server sends the email to the recipient or another forwarding proxy.

SMTP (Simple Mail Transfer Protocol) Simple Mail Transfer Protocol

It is the TCP/IP protocol used to send emails. Its content is defined by RFC 821 of IETF. Another protocol with the same features as SMTP is x.400. An important feature of SMTP is its ability to transmit mails during transmission. The transfer service provides an inter-process communication environment (ipce), which can include a network, several networks or subnets of one network. It is important to understand that the transfer system (or ipce) is not one-to-one. The process may directly communicate with other processes through known ipce. An email is an application or inter-process communication. Emails can be sent across the network through processes connected to different ipce. More specifically, emails can be transmitted over hosts on different networks.

Talk Protocol

The Talk Protocol enables two users on the remote computer to communicate in real time.

TCP/IP (Transmission Control Protocol/Internet Protocol) Transmission Control Protocol/Internet Protocol

The TCP/IP protocol originated from the US Defense Advanced Research Plan. The protocol that provides reliable data transmission is called the transmission control protocol TCP. For example, the cargo packing list ensures that data is not lost during transmission. The protocol that provides the connectionless datagram service is called the Network Protocol IP address, it is like the address and name of the recipient to ensure that the data arrives at the specified location. TCP/IP is a widely used protocol on the Internet. The main services provided by the Internet using TCP/IP are: email, file transfer, remote logon, network file system, video conferencing system, and World Wide Web. It is the foundation of Interent. It provides the routing function within the WAN and allows different hosts on the Internet to be interconnected. In concept, it can be mapped to four layers: the network interface layer, which is responsible for transmitting frames on the line and receiving frames from the line; the Internet layer, which includes the IP protocol, the IP protocol generates Internet datagram and carries out necessary routing algorithms. The IP protocol can be divided into four parts: ARP, ICMP, IGMP, and IP. the uplink layer is the transport layer, this layer is responsible for managing sessions between computers. This layer includes two protocols, TCP and UDP. Different Application requirements can communicate using different protocols. The last layer is the application layer, we are familiar with FTP, DNS, and telnet. Familiarity with TCP/IP is the only way to get familiar with the Internet.

Telnet protocol virtual terminal Protocol

The telnet protocol is designed to provide a common, bidirectional, eight-byte-oriented communication method, its main goal is to allow standard methods of interface terminal devices and terminal-oriented interaction. Is to allow users to log on to the remote computer and use all resources open to the outside world on the remote computer.

Time Protocol

This Protocol provides a machine-readable date and time information independent from the site. The time service returns the number of seconds, from midnight on January 1, January 1, 1900 to the current number of seconds. An important purpose of designing this protocol is that many hosts on the network do not have the concept of time. In a distributed system, we can think about it, how is the time between Beijing time and Tokyo time? The host time can often be changed manually, and is inconsistent because of the error in the machine clock. Therefore, you need to use the time server to obtain the network time through election, let the server have an accurate concept of time. Don't underestimate the time. This is too important for some time-based distributed programs. This protocol can work under TCP and UDP protocols. The time is represented by 32 bits, which is the number of seconds from 0 o'clock on January 1, January 1, 1900 to the current time. We can calculate that this protocol can only be used until January 1, 2036, however, we also know that computers are growing so fast that there may be better protocols to replace this protocol.

TFTP (Trivial File Transfer Protocol) Small File Transfer Protocol

It is a network application, which is simpler than FTP and has fewer functions than FTP. It is used without user permissions or directory visibility. It uses UDP protocol instead of TCP protocol.

User Data Protocol (UDP)

It is a protocol used to provide Packet Exchange for computer communication in the interconnection network environment. By default, this Protocol considers the network protocol (IP) as its underlying protocol. UDP is another method of TCP. Like TCP, UDP uses the IP protocol to obtain data units (called datagram). Unlike TCP, UDP does not provide packets (datagram) group and assemble services. In addition, it does not provide sorting of packages, which means that the program must determine whether the information is completely accurate to the destination. If network programs want to speed up processing, it is better to use UPD than TCP. UDP provides two services not provided by the IP layer. It provides port numbers to differentiate requests of different users and provides parity. In OSI Mode, UDP and TCP are on the fourth layer and transport layer.

UUCP (Unix-to-Unix CoPy protocol) UNIX to Unix CoPy Protocol

It is a set of commands used to copy (transfer) files or send commands to execute commands on other UNIX systems. It is the basis of the UNIX network.

X.25 Protocol

It is a CCITT standard communication protocol established in 1976 and is used to define data packets for synchronous transmission. It is a protocol used internationally on the Group Data Network (pdn. It allows computers in different networks to communicate with each other through an intermediate computer working at the network layer.

X.400 Protocol

It is an email protocol, which is developed by the ITU-TS and can play the same functionality as SMTP. X.400 is widely used in Europe and Canada. It is actually a standard set, and each standard serial number is between 400 and 499. The x.400 address can provide functions that cannot be provided by many SMTP addresses. Therefore, the x.400 address is long and troublesome. X.400 does provide more functions than SMTP, but these functions are rarely used. The main components of x.400 include: User proxy (UA), message transmission proxy (MTA), and message transmission system (MTS ).

Z39.50 protocol

It is a standard communication protocol used to retrieve and obtain book directories in online databases. Z39.50 is used to retrieve the Library's Online Public Access Directory (OPAC) on the Internet. It can also be used to connect multiple separated OPAC, Which is ANSI/NiSO standard.