20160402_TCP/IP Protocol Cluster

Original question:

In the following description of the ICMP protocol, the correct is ()

A. The ICMP protocol finds the corresponding IP address based on the MAC address

B. The ICMP protocol translates the IP address of the public network into the IP address of the private network

C. ICMP protocol for controlling error conditions in datagram delivery

D. IP address assignment in the centralized Management network of the ICMP protocol

Answer:

C

Knowledge Points:

Network

Rarp Protocol (Reverse address Resolution Protocol): Find the corresponding IP address based on the MAC address.

NAT Protocol (Network address translation): Converts the IP address of the public network to the IP address of the private network.

ICMP protocol (Internet control message protocol,internet controlled message protocol): Used to control error conditions in datagram delivery.

DHCP protocol (Dynamic Host configuration Protocol): Used to centrally manage IP address assignment in the network.

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TCP/IP protocol cluster

The TCP/IP protocol cluster is the foundation of the Internet and is the most popular form of networking today. TCP/IP is synonymous with a set of protocols, including many other protocols that make up the TCP/IP protocol cluster. Among the more important are slip protocol, PPP protocol, IP Protocol, ICMP protocol, ARP protocol, TCP protocol, UDP protocol, FTP protocol, DNS protocol, SMTP protocol, etc. The TCP/IP protocol does not fully conform to the OSI seven-layer reference model. The traditional open System Interconnect Reference Model is a 7-layer abstract reference Model for communication protocols, where each layer performs a specific task. The purpose of this model is to enable various hardware to communicate with each other at the same level. The TCP/IP protocol uses a 4-tier hierarchy, each of which calls the network provided by its next layer to fulfill its own needs.

Slip protocol slip provides a simple way to encapsulate IP packets on a serial communication line, allowing remote users to easily access TCP/IP networks via telephone lines and modems. Slip is a simple framing method, but there are some problems with it. First of all, slip does not support the dynamic IP address assignment During the connection process, the communication parties must inform each other's IP address beforehand, which brings great inconvenience to the Internet network of the individual users without fixed IP address. Secondly, there is no check field in the slip frame, so the error can not be detected on the link layer, and the transmission error problem must be solved by the upper entity or the modem with error correction capability.  PPP protocol in order to solve the problem of slip, the PPP protocol has been developed in the serial communication application. PPP protocol is an effective point-to-point communication protocol, which is composed of a group frame method on serial communication line, a Link control protocol LCP for establishing, preparing, testing and removing data link, and a set of network control protocol NCPs to support different network layer protocols. The LCP protocol in PPP provides the means of parameter negotiation for both parties, and provides a set of NCPS protocols, so that PPP can support various network layer protocols, such as Ip,ipx,osi. In addition, the IP-enabled NCP provides the ability to dynamically assign IP addresses when establishing links, which solves the problem of Internet network on individual users. The  IP protocol is the Internet Protocol (Internet Protocol), which connects multiple networks into one internet, which distributes high-level data over the Internet in multiple packets. The basic task of IP is to transmit packets over the Internet, and each IP packet is independent of each other. The  ICMP protocol is the Internet Control Message protocol. From the function of IP Internet Protocol, it can be known that IP provides an unreliable packet transfer service for non-connected packets. If the router or host fails when the network is blocked, you need to notify the sending host to take the appropriate action. To enable the Internet to report errors, or to provide information about contingencies, a special-purpose message mechanism, ICMP, is added to the IP layer. The packet receiver uses ICMP to notify the IP module sender of the necessary modifications. ICMP is usually generated by the station where the packet is found to be problematic, such as ICMP that can be detected and generated by the destination host or relay router. If a packet cannot be delivered, ICMP can be used to warn the packet source that there is a network, the host, or the port is unreachable. ICMP can also be used to report network congestion. The  ARP protocol is the address translation protocol. In a TCP/IP network environment, each host is assigned a 32-bit IP address, which is a logical address that identifies the host in the internetwork. In order for messages to be transmitted on a physical network, it is necessary to know each other's physical address. So there's the Internet addressTransform into a physical address conversion problem. This requires a set of services at the network layer to translate the IP address into the corresponding physical network address, which is the set of protocols, ARP. The  TCP protocol is the transmission protocol, which provides a reliable data flow service. When transmitting error-disturbed data, or citing network failure, or the network load is too heavy to make the Internet basic transmission system can not work properly, it is necessary to use other protocols to ensure reliable communication. TCP is such a protocol. TCP uses the "positive confirmation with retransmission" technique to achieve the reliability of the transmission. and use the "sliding window" flow control mechanism to improve the network throughput. TCP communication establishes the concept of a "virtual circuit". Before the two parties communicate, a link is established before both parties can send the data stream on it. This type of data exchange can improve efficiency, but the overhead of establishing a connection beforehand and removing the connection afterwards is necessary. The  UDP protocol, the user Packet protocol, is an extension of the IP protocol group, which adds a mechanism by which the sender can differentiate multiple receivers on a single computer. Each UDP message contains the number of the destination port of the message and the number of the source port in addition to the data, so that the UDP software can deliver the message to the correct receiver, and then the receiver sends out a reply. This expansion of UDP makes it possible to deliver packets between two user processes. The OICQ software we use frequently is based on the UDP protocol and this mechanism. The  FTP protocol, the file Transfer Protocol, is an internetwork protocol for accessing remote machines, allowing users to operate on files between the local machine and the remote machine. FTP works by establishing two TCP links, respectively, for transferring files and for transmitting control. Does FTP use client/server mode? It contains client FTP and server FTP. The client FTP initiates the transfer process, and the server FTP responds to it. The  DNS protocol, the Domain Name Service protocol, provides domain-to-IP conversion, allowing decentralized management of domain name resources. The purpose of DNS was originally designed to enable mail senders to know the IP address of the receiving host and the mail sending host, and later to evolve into protocols that serve many other goals.  SMTP protocol is Simple Mail delivery protocol e-mail in the Internet standard is a simple text-based protocol for reliable and efficient data transmission. SMTP is a service of the application layer and does not care what transport service it uses, it can transmit mail over the TXP link over the network, or simply send the message through the process communication channel between processes of the same machine, so that the message transport is independent of the transport subsystem and can be tcp/ Transport messages in an IP environment or in the X. Protocol environment.

20160402_TCP/IP Protocol Cluster