简答及名字解释

简答及名字解释 问答题及名字解释 1计算机网络组成的三要素是什么, 答:计算机及辅助设备(HUB集线器)、通信介质(导线、无线)、网络软件(Windows NT、Novell) 2计算机网络的发展可划分为几个阶段,每个阶段各有何特点, 答:可分为四个阶段。 第一阶段为面向终端的计算机网络，特点是由单个具有自主处理功能的计算机和多个没有自主处理功能的终端组成网络。 第二阶段为计算机-计算机网络，特点是由具有自主处理功能的多个计算机组成独立的网络系统。 第三阶段为开放式 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 化网络，特点是由多个计算机组成容易实现网络之间互相连接的开放式网络系统。 第四阶段为因特网的广泛应用与高速网络技术的发展，特点是网络系统具备高度的可靠性与完善的管理机制，网络覆盖范围广泛。 3计算机网络可从几方面进行分类, 答1.从网络结点分布来看，可分为局域网(Local Area Network，LAN)、广域网(Wide Area Network，WAN)和城域网(Metropolitan Area Network，MAN)。 2.按交换方式可分为线路交换网络(Circurt Switching)、报文交换网络(Message Switching)和分组交换网络(Packet Switching)。 3.按网络拓扑结构可分为星型网络、树型网络、总线型网络、环型网络和网状网络 4网络 协议 离婚协议模板下载合伙人协议 下载渠道分销协议免费下载敬业协议下载授课协议下载 的三要素是什么,各有什么含义, 答(1) 语义。语义是解释控制信息每个部分的意义。它规定了需要发出何种控制信息，以及完成的动作与做出什么样的响应。 (2) 语法。语法是用户数据与控制信息的结构与格式，以及数据出现的顺序。 (3) 时序。时序是对事件发生顺序的详细说明。(也可称为“同步”)。[ 5面向连接和无连接服务有何区别, 答:面向连接:信息是从一条早已经建好的线路上传，中间不会有什么变化 面向无连接:信息的传递线路是在发起传递前临时建立的，传完以后线路就会没有 l已知主机的IP地址为211.81.192122(请确定该主机所在网络的类别 网络号及其主机号 2已知主机IP地址为167.81(123.255.清确定该主机所在的网络的类别、网络号及其主机号 3某单位分到一个B类IP地址，其网络ID为156. 12.0.0.该单位有4000多台计算机，分布在16个不同的地点.试给每一个地点分配一个子网号码，并计算每个地址主机号码的最小值和最大值 4假设有一组C类IP地址为192. 168.32.0-192. 168.63.0.如果用CIDR将这组地址聚合为一个网络其网络地址和子网掩码为多少 5.一个主机的IP地址是202.112.14.137(掩码为:255.255.255.224要求计算这个主机所在网络的网络地址和广播地址 enforced thermal insulation starts checking system, issued by the thermal insulation construction before you start to notice, transfer inspection of upper and lower operation and transfer of records. For outdoor operation, pipeline equipment to effectively carry out the insulation waterproof measures fail to install protective panels in part with three tarpaulin cover, to prevent insulation from moisture. Insulation seam Michael Jackson 5mm, joints, joints >100mm, insulation thickness tolerance (+10MM~ – 5mm), appropriate material elastic banding, spacing according to the design requirements, rigid insulation soft materials for construction joints tight; And large-diameter vertical pipe for high temperature pipeline in strict accordance with design drawings called for the establishment of expansion joints and holding bracket; Design requirements into a removable type of insulation, in strict accordance with specifications disconnect from the other insulation; Surface insulation boards in the technology of plastering construction of woven cloth to prevent pollution and protective panels flush with the surface interface, tight and clean. Site measurement of insulation boards for elbow shape cutting, ensure that each piece of lapped traffic, arc transition of natural, beautiful, screws up. Stampede outside construction personnel is strictly prohibited and shelve objects directly on the outer shield. In order to prevent the pollution-prone heater, channel area of secondary pollution of large-diameter pipes and other equipment, weaving cloth, and erection of the separation platform for preservation. Thermal insulation construction, on-hook tack welded to the consolidated line, to ensure evenly spaced, and the hook nailed down ... See next page flow chart management process. 7.2 General requirements for protective product protection 6IP协议中规定的特殊IP地址有哪些,各有什么用途, 答 1. 127.0.0.1本机地址，主要用于测试。 2. 255.255.255.255 限制广播地址。对本机来说，这个地址指本网段内(同一广播域)的所有主机 3. 0.x.x.x、172.16.x.x,172.31.x.x、192.168.x.x 私有地址，这些地址被大量用于内部网络中。使用私有地址的私有网络在接入Internet时，要使用地址翻译 (NAT)，将私有地址翻译成公用合法地址。在Internet上，这类地址是不能出现的. 4. 169.254.x.x 如果你的主机使用了DHCP功能自动获得一个IP地址，那么当你的DHCP服务器发生故障，或响应时间太长而超出了一个系统规定的时间. 5. 224.0.0.1 组播地址，224.0.0.1特指所有主机， 224.0.0.2特指所有路由器。这样的地址多用于一些特定的程序以及多媒体程序。 6. 0.0.0.0 严格说来，0.0.0.0已经不是一个真正意义上的IP地址。它表示的是这样一个集合:所有不清楚的主机和目的网络。 7路由器和网桥相比有哪些区别 1.网桥是第二层的设备，而路由器是第三层的设备; 2 网桥只能连接两个相同相似的网络，而路由器可以连接不同网络; 3.网桥不隔离广播，而路由器可以隔离广播 8路由器在网络互连中有哪些作用 答:第一，网络互连，路由器支持各种局域网和广域网接口，主要用于互连局域网和广域网，实现不同网络互相通信; 第二，数据处理，提供包括分组过滤、分组转发、优先级、复用、加密、压缩和防火墙等功能; 第三，网络管理，路由器提供包括配置管理、性能管理、容错管理和流量控制等功能 9为什么需要动态路由 动态路由是指路由器能够自动地建立自己的路由表，并且能够根据实际情况的变化适时地进行调整 由于静态路由系统不能对网络改变做出反映，通常被认为不适用于现在的大型、易变的网络 10动态路由选择是如何工作的 路由器负责将数据分组从源端主机经过最佳路径传送到目的端主机 11局域网参考模型的数据链路层分为哪几层,各层的功能是什么, 局域网参考模型的数据链路层分为逻辑链路控制LLC子层和介质访问控制MAC子层。 MAC子层主要功能是进行合理的信道分配，解决信道竞争问题。 LLC子层的作用是在MAC子层提供的介质访问控制和物理层提供的比特服务的基础上，将不可靠的信道处理为可靠的信道，确保数据帧的正确传输。 enforced thermal insulation starts checking system, issued by the thermal insulation construction before you start to notice, transfer inspection of upper and lower operation and transfer of records. For outdoor operation, pipeline equipment to effectively carry out the insulation waterproof measures fail to install protective panels in part with three tarpaulin cover, to prevent insulation from moisture. Insulation seam Michael Jackson 5mm, joints, joints >100mm, insulation thickness tolerance (+10MM~ – 5mm), appropriate material elastic banding, spacing according to the design requirements, rigid insulation soft materials for construction joints tight; And large-diameter vertical pipe for high temperature pipeline in strict accordance with design drawings called for the establishment of expansion joints and holding bracket; Design requirements into a removable type of insulation, in strict accordance with specifications disconnect from the other insulation; Surface insulation boards in the technology of plastering construction of woven cloth to prevent pollution and protective panels flush with the surface interface, tight and clean. Site measurement of insulation boards for elbow shape cutting, ensure that each piece of lapped traffic, arc transition of natural, beautiful, screws up. Stampede outside construction personnel is strictly prohibited and shelve objects directly on the outer shield. In order to prevent the pollution-prone heater, channel area of secondary pollution of large-diameter pipes and other equipment, weaving cloth, and erection of the separation platform for preservation. Thermal insulation construction, on-hook tack welded to the consolidated line, to ensure evenly spaced, and the hook nailed down ... See next page flow chart management process. 7.2 General requirements for protective product protection 12在TCP/IP协议中各层有哪些主要协议, OSI中的功能 TCP/IP协议族 层 文件传输，电子邮件，文件服务，虚TFTP，HTTP，SNMP，FTP，SMTP，DNS，Telnet 应用层 拟终端 等等 表示层 翻译、加密、压缩 没有协议 会话层 对话控制、建立同步点(续传) 没有协议 端口寻址、分段重组、流量、差错控传输层 TCP，UDP 制 网络层 逻辑寻址、路由选择 IP，ICMP，OSPF，EIGRP，IGMP 数据链路成帧、物理寻址、流量，差错，接入SLIP，CSLIP，PPP，MTU 层 控制 应用层,应用程序间沟通的层，如简单电子邮件传输(SMTP)、文件传输协议(FTP)、网络远程访问协议(Telnet)等。 传输层,在此层中，它提供了节点间的数据传送，应用程序之间的通信服务，主要功能是数据格式化、数据确认和丢失重传等。如传输控制协议(TCP)、用户数据报协议(UDP)等，TCP和UDP给数据包加入传输数据并把它传输到下一层中，这一层负责传送数据，并且确定数据已被送达并接收。 互连网络层,负责提供基本的数据封包传送功能，让每一块数据包都能够到达目的主机(但不检查是否被正确接收)，如网际协议(IP)。 网络接口层,主机-网络层,,接收IP数据报并进行传输，从网络上接收物理帧，抽取IP数据报转交给下一层，对实际的网络媒体的管理，定义如何使用实际网络(如Ethernet、Serial Line等)来传送数据 应用层 例如HTTP、SMTP、SNMP、FTP、Telnet、SIP、SSH、NFS、RTSP、XMPP、Whois、ENRP 7 表示层 例如XDR、ASN.1、SMB、AFP、NCP 6 会话层 例如ASAP、TLS、SSH、ISO 8327 / CCITT X.225、RPC、NetBIOS、ASP、Winsock、BSD sockets 5 传输层 例如TCP、UDP、RTP、SCTP、SPX、ATP、IL 4 网络层 例如IP、ICMP、IGMP、IPX、BGP、OSPF、RIP、IGRP、EIGRP、ARP、RARP、 X.25 3 数据链路 例如Ethernet、Token ring、HDLC、Frame relay、ISDN、ATM、802.11 WiFi、FDDI、PPP 2 层 enforced thermal insulation starts checking system, issued by the thermal insulation construction before you start to notice, transfer inspection of upper and lower operation and transfer of records. For outdoor operation, pipeline equipment to effectively carry out the insulation waterproof measures fail to install protective panels in part with three tarpaulin cover, to prevent insulation from moisture. Insulation seam Michael Jackson 5mm, joints, joints >100mm, insulation thickness tolerance (+10MM~ – 5mm), appropriate material elastic banding, spacing according to the design requirements, rigid insulation soft materials for construction joints tight; And large-diameter vertical pipe for high temperature pipeline in strict accordance with design drawings called for the establishment of expansion joints and holding bracket; Design requirements into a removable type of insulation, in strict accordance with specifications disconnect from the other insulation; Surface insulation boards in the technology of plastering construction of woven cloth to prevent pollution and protective panels flush with the surface interface, tight and clean. Site measurement of insulation boards for elbow shape cutting, ensure that each piece of lapped traffic, arc transition of natural, beautiful, screws up. Stampede outside construction personnel is strictly prohibited and shelve objects directly on the outer shield. In order to prevent the pollution-prone heater, channel area of secondary pollution of large-diameter pipes and other equipment, weaving cloth, and erection of the separation platform for preservation. Thermal insulation construction, on-hook tack welded to the consolidated line, to ensure evenly spaced, and the hook nailed down ... See next page flow chart management process. 7.2 General requirements for protective product protection 物理层 例如wire、radio、fiber optic、Carrier pigeon 1 1(简述物理层在OSI模型中的地位和作用。 答:物理层是OSI模型七层结构的第一层，他向下直接与传输介质相连接，是开放系统的物理传输介质的借口，向上相邻且服务服务于数据链路层。物理层的功能就是实现在传输介质上的传输介质上传输各种数据的比特流 2(物理层协议包括哪些方面的内容,为什么要做出这些规定, 物理层协议定义了数据终端设备和数据电路端接设备之间的接口 规范 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 和标准。由于传输距离和传输技术的不同，局域网和广域网使用的物理接口和标准也不一样。因此要做出这些规定。 3(DTE和DCE是什么，它们对应于网络中那些设备, DTE:数据终端设备，具有一定的数据处理能力和数据收发能力的设备。一般广域 网常用DTE设备有:路由器，终端主机 DCE:数据通信设备，他在DTE和传输线路之间提供信号变换和编码功能，并负责 建立，保持和释放链路的链接。一般广域网常用DCE设备有:CSU/DSU，广域网交 换机，MODEM 4(请比较巾继器和集线器作为物理层网络互连设备的异同。 中继器具有对物理信号进行放大和再生的功能，其将从输入接口接收的物理信号通 过放大和整形再从输出接口输出。中继器具有典型的单进单出结构。集线器在物理上 被 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 成集中式的多端口中继器，其多个端口可为多路信号提供放大、整形和转发功 能。多端口的集线器除了中继器的功能外，相当于提供了网络线缆连接的一个集中点， 并可增加网络连接的可靠性 5(交换机是如何转发数据帧的, 1、已知单播帧(即MAC地址表有记录):从指定端口转发 2、未知单播帧(即MAC地址表没有记录):泛洪到所有端口除了接收口 3、广播帧:泛洪到所有端口除了接收口 转发方式:直通转发方式，存储转发方式、无碎片转发 1、多路复用技术:为了提高通信线路的利用率，在一个信道上同事或分时为多用户服务的技术。 2、协议:在计算机网络技术中，为了保证通信双反能正确地、自动的进行数据通信，针对通信过程的各种情况，制定了一整套约定，这就是网络系统的通信协议。 3、子网掩码:是32位二进制数，它的子网标识部分为全“0”.利用子网掩码可以判断两台主机是否在同一子网中。若两台主机的IP地址分别与他们的子enforced thermal insulation starts checking system, issued by the thermal insulation construction before you start to notice, transfer inspection of upper and lower operation and transfer of records. For outdoor operation, pipeline equipment to effectively carry out the insulation waterproof measures fail to install protective panels in part with three tarpaulin cover, to prevent insulation from moisture. Insulation seam Michael Jackson 5mm, joints, joints >100mm, insulation thickness tolerance (+10MM~ – 5mm), appropriate material elastic banding, spacing according to the design requirements, rigid insulation soft materials for construction joints tight; And large-diameter vertical pipe for high temperature pipeline in strict accordance with design drawings called for the establishment of expansion joints and holding bracket; Design requirements into a removable type of insulation, in strict accordance with specifications disconnect from the other insulation; Surface insulation boards in the technology of plastering construction of woven cloth to prevent pollution and protective panels flush with the surface interface, tight and clean. Site measurement of insulation boards for elbow shape cutting, ensure that each piece of lapped traffic, arc transition of natural, beautiful, screws up. Stampede outside construction personnel is strictly prohibited and shelve objects directly on the outer shield. In order to prevent the pollution-prone heater, channel area of secondary pollution of large-diameter pipes and other equipment, weaving cloth, and erection of the separation platform for preservation. Thermal insulation construction, on-hook tack welded to the consolidated line, to ensure evenly spaced, and the hook nailed down ... See next page flow chart management process. 7.2 General requirements for protective product protection 网掩码相“与”后的结果相同，则说明这两台主机在同一子网中。 4、带宽:指通过给定线路发送的数据量，从技术角度看，宽带是通信信道的宽度，单位是赫兹 5、计算机网络:计算机网络是将分布在不同地理位置上的具有独立工作能力的计算机、终端及其附属设备的通信线路连接起来，并配置网络软件，以实现计算机资源共享的系统。 1、有10个站连接到以太网上，计算以下三种情况下每一个站所能得到的带宽。 (1)、10个站都连接到一个10Mbit/s以太网集线器; (2)、10个站都连接到一个100Mbit/s以太网集线器; (3)、10个站都连接到一个10Mbit/s以太网交换机。 (1)、10M/10=1M (2)、100M/10=10M (3)、10M 2、CSMA/CD的工作原理, (1)、多点接入，许多计算机一多点接入的方式连接在一根总线上。协议的实质是“载波监听”和“多路访问”。(2)、载波监听指每一个站在发送数据之前要 检测 工程第三方检测合同工程防雷检测合同植筋拉拔检测方案传感器技术课后答案检测机构通用要求培训 一下总线上是否有其他计算机在发送数据，如果有，则暂时不要发送数据，以免发生碰撞。 3、说明IP地址于硬件地址的区别。 IP地址是个每个连接在英特网上的主机分配一个全世界范围内唯一的32位的标识符。IP地址可分为5类。是网络层和以上各层使用的地址，IP地址放在IP数据报的首部。硬件地址是MAC地址或物理地址，是网卡地址或网卡标志符，共48位。是数据链路层和物理层使用的地址。放在MAC帧的首部。 、什么是局域网,有什么特点, 4 局域网是一种通信网络，支持各种数据通信设备间的设备互联、信息交换和资源共享。主要特点是:(1)覆盖地理范围小，所有的站点共享较高的总宽带(即较高的数据传输速率(一般大于10Mbps，可达1Gbps);(2)具有较小的时延和较低的误码率;(3)各站点之间形成平等关系而不是从主关系。(4)能进行广播或多播 enforced thermal insulation starts checking system, issued by the thermal insulation construction before you start to notice, transfer inspection of upper and lower operation and transfer of records. For outdoor operation, pipeline equipment to effectively carry out the insulation waterproof measures fail to install protective panels in part with three tarpaulin cover, to prevent insulation from moisture. Insulation seam Michael Jackson 5mm, joints, joints >100mm, insulation thickness tolerance (+10MM~ – 5mm), appropriate material elastic banding, spacing according to the design requirements, rigid insulation soft materials for construction joints tight; And large-diameter vertical pipe for high temperature pipeline in strict accordance with design drawings called for the establishment of expansion joints and holding bracket; Design requirements into a removable type of insulation, in strict accordance with specifications disconnect from the other insulation; Surface insulation boards in the technology of plastering construction of woven cloth to prevent pollution and protective panels flush with the surface interface, tight and clean. Site measurement of insulation boards for elbow shape cutting, ensure that each piece of lapped traffic, arc transition of natural, beautiful, screws up. Stampede outside construction personnel is strictly prohibited and shelve objects directly on the outer shield. In order to prevent the pollution-prone heater, channel area of secondary pollution of large-diameter pipes and other equipment, weaving cloth, and erection of the separation platform for preservation. Thermal insulation construction, on-hook tack welded to the consolidated line, to ensure evenly spaced, and the hook nailed down ... See next page flow chart management process. 7.2 General requirements for protective product protection