CCNA 2 Chapter 11 v5.0 Exam Answers 2013

1. Which statements correctly identify the role of intermediary devices in the network? (Choose three.)determine pathways for data 确定数据通路initiate data communicationsretime and retransmit data signals 重分发originate the flow of datamanage data flows 管理数据final termination point for data flow2. Select the statements that are correct concerning network protocols. (Choose three.)define the structure of layer specific PDU'sdictate how to accomplish layer functionsoutline the functions necessary for communications between layers limit the need for hardware compatibilityrequire layer dependent encapsulationseliminate standardization among vendors3. What are two functions of encapsulation? (Choose two.)tracks delay between end devicesenables consistent network paths for communicationallows modification of the original data before transmissionidentifies pieces of data as part of the same communicationensures that data pieces can be directed to the correct receiving end device4. What is a primary function of the trailer information added by the data link layer encapsulation?supports error detection 支持错误检测‘ensures ordered arrival of dataprovides delivery to correct destinationidentifies the devices on the local networkassists intermediary devices with processing and path selection5. Which statements correctly identify the role of intermediary devices in the network? (Choose three.)determine pathways for datainitiate data communicationsretime and retransmit data signalsoriginate the flow of datamanage data flowsfinal termination point for data flow6. What is a PDU?corruption of a frame during transmissiondata reassembled at the destinationretransmitted packets due to lost communicationa layer specific encapsulation 一个具体的封装层7. Which characteristic correctly refers to end devices in a network?manage data flowsoriginate data flow 原数据流retime and retransmit data signalsdetermine pathways for data8.Refer to the exhibit. "Cell A" at IP address 10.0.0.34 has established an IP session with "IP Phone 1" at IP address 172.16.1.103. Based upon the graphic, which device type best describes the function of wireless device "Cell A?"the destination devicean end devicean intermediate devicea media device9.Refer to the exhibit. Which three labels correctly identify the network types for the network segments that are shown?(Choose three.)Network A -- WANNetwork B -- WANNetwork C -- LANNetwork B -- MANNetwork C -- WANNetwork A -- LAN10. Which three statements best describe a Local Area Network (LAN)? (Choose three.)A LAN is usually in a single geographical area.The network is administered by a single organization.The connection between segments in the LAN is usually through a leased connection.The security and access control of the network are controlled by a service provider.A LAN provides network services and access to applications for users within a common organization.Each end of the network is generally connected to a Telecommunication Service Provider (TSP).11.Refer to the exhibit. Which networking term describes the data interleaving process represented in the graphic?pipingPDUstreamingmultiplexingencapsulation12. What is the primary purpose of Layer 4 port assignment?to identify devices on the local mediato identify the hops between source and destinationto identify to the intermediary devices the best path through the network to identify the source and destination end devices that are communicating to identify the processes or services that are communicating within the end devices13. What device is considered an intermediary device?1．file serve2.IP phone ptop 4.printer 5.switch14.Refer to the exhibit. Which term correctly identifies the device type that is included in the area B? sourceendtransferintermediary 中间设备15.Refer to the exhibit. What type of network is shown?WANMANLANWLAN16. Which layer encapsulates the segment into packets?physicaldata linknetwork 网络层封装的是数据包transport17. What can be identified by examining the network layer header?the destination device on the local mediathe destination host address 网络层头部封装目的主机的地址the bits that will be transferred over the mediathe source application or process creating the data18. What is the purpose of the TCP/IP Network Access layer?path determination and packet switchingdata presentationreliability, flow control, and error detectionnetwork media control 接入层控制网络媒体the division of segments into packets19. During the encapsulation process, what occurs at the data link layer? No address is added.The logical address is added.The physical address is added. 数据链路层添加一个物理地址The process port number is added.20.Refer to the exhibit. Which set of devices contains only end devices? A, C, DB, E, G, HC, D, G, H, I, JD, E, F, H, I, JE, F, H, I, J21. What is the proper order of the layers of the OSI model from the highest layer to the lowest layer?4physical, network, application, data link, presentation, session, transportapplication, physical, session, transport, network, data link, presentationapplication, presentation, physical, session, data link, transport, networkapplication, presentation, session, transport, network, data link, physicalpresentation, data link, session, transport, network, physical, application22. Which two layers of the OSI model have the same functions as the TCP/IP model Network Access Layer? (Choose two.)34NetworkTransportPhysicalData Link TCP/IP 工作在第一层和第二层Session。

yy1 ・ Refer to the exhibit・ Identify the devices labeled A, B, C, and D in the network physical documentation. 匚A=bridge, B=switch, C=router, D=hubK A=bridge, B=hub, C=router, D=switchC A=bridge, B=router, C=hub, D=switchc A=hub, B=bridge, C=router, D=switch2 The central hub has malfunctioned in the network. As a result, the entire network is down. Which type of physical network topology is implemented?匚busE starC ring匚mesh3. A switch has failed in the network. As a result, only one segment of the network is down. Which type of physical network topology is implemented?C busC ring匚starE extended star4. Which three features apply to LAN connections? (Choose three.)厂operate using serial in terfacesV make network connection using a hubV limited to operation over small geographic areas厂 provide part-time connectivity to remote servicesV typically operate under local administrative control厂provide lower bandwidth services compared to WANs5. What is one advantage of defining network communication by the seven layers of the OSI model? 【:It in creases the ban dwidth of a n etwork.E It makes networking easier to learn and understand・It eliminates many protocol restrictions.匚It increases the throughput of a network.c It reduces the need for testing network connectivity.6. What makes it easier for different networking vendors to design software and hardware that willin teroperate?E OSI modelc proprietary desig ns匚IP addressing schemec standard logical topologies匚standard physical topologies7. Which term describes the process of adding headers to data as it moves down OSI layers?匚division匚encoding匚separation匚segmentationE encapsulation8. What is the term used to describe the transport layer protocol data unit?匚bits c packetsE segments匚framesc data streams9. Which of the following are layers of the TCP/IP model? (Choose three.)▽ Applicati onr PhysicalV Internet0 Network Access厂Prese ntation10. Which of the following are data link layer encapsulation details? (Choose two.)0 A header and trailer are added・厂Data is con verted into packets ・V Packets are packaged into frames・厂Frames are divided into segments.厂Packets are changed into bits for Internet travel.11. Which layer of the OSI model provides network services to processes in electronic mail and file transfer programs?匚data link匚transport匚n etworkE application12. Which two features apply to WAN connections? (Choose two.)V operate using serial interfacesP make network connection using a hub厂limited to operation over small geographic areasI- typically operate under local administrative control▽provide lower bandwidth services compared to LANs13. Which of the following are ways that bandwidth is commonly measured? (Choose three.)厂GHzps▽kbpsV Mbps厂Nbps厂MHzpsV Gbps14. Refer to the following list. Choose the correct order of data encapsulation when a device sends information. segments bits packetsdata frames匚1 -3-5-4-2C 2- 1-3-5-4C 2-4-3-5-1匚4-3-1-2-5E 4-1 -3-5-2C 3-5-1-2-415. Which of the following are factors that determine throughput? (Choose two.)厂types of passwords used on servers厂type of Layer 3 protocol usedV n etwork topologywidth of the network cable0 number of users on the network16. Refer to the exhibit・ Which column shows the correct sequenee of OSI model layers?E D17. Which layer of the OSI model provides connectivity and path selection between two end systems where routing occurs?c physical layer匚data link layerE network layer匚transport layer18. Which best describes the function of the physical layer?E Defines the electrical and functional specifications for the link between end systems・匚Provides reliable transit of data across a physical link.匚Provides connectivity and path selection between two end systems・匚Concerned with physical addressing, network topology and media access.。

1. What action does a link-state router take immediately upon receipt of an LSP from a neighboring router?floods the LSP to neighborscalculates the SPF algorithmruns the Bellman-Ford algorithmcomputes the best path to the destination network2. Why is it difficult for routing loops to occur in networks that use link-state routing?Each router builds a simple view of the network based on hop count. Routers flood the network with LSAs to discover routing loops.Each router builds a complete and synchronized view of the network. Routers use hold-down timers to prevent routing loops.3.Refer to the exhibit. What kind of information would be seen in an LSP sent from router JAX to router ATL?hop countuptime of the routecost of the linka list of all the routing protocols in use4. To achieve network convergence, what three steps does each link state router take? (Choose three.)use automatic summarization to reduce the size of routing tablesbuild a Link State Packet (LSP) containing the state of each directly connected linkflood the LSP to all neighbors, who then store all LSPs received in a databasediscover neighbors and establish adjacencies using the hello packet sent at regular intervalsconstruct a complete map of the topology and compute the best path to each destination networkuse the DUAL FSM to select efficient, loop-free paths, and insert routes into the routing table5.Refer to the exhibit. When Router D is configured to use a link-state routing protocol and is added to the network, what is the first thing that it does to begin learning the network topology?It sends LSP packets to Routers B and C.It sends LSP packets to all routers in the network.It sends Hello packets to all routers in the network.It sends information about its directly connected neighbors to Routers A and E.It sends information about its directly connected neighbors to all routers in the network.It learns about its directly connected networks when its interfaces reach the up state.6. A new network administrator is given the task of selecting an appropriate dynamic routing protocol for a software development company. The company has over 100 routers, uses CIDR and VLSM, requires fast convergence, and uses both Cisco and non-Cisco equipment. Which routing protocol is appropriate for this company?RIP version 2IGRPEIGRPOSPFBGP7. What two events will cause a link state router to send LSPs to all neighbors? (Choose two.)30 second timer expireswhenever the network topology changesimmediately after the Bellman-Ford algorithm has runimmediately after the DUAL FSM has built the topology databaseupon initial startup of router or routing protocol8. What is the final step in the link state routing process? successors are placed into the routing tableSPF computes best path to each destination networkLSPs are flooded to all neighbors to converge the networkDUAL algorithm is run to find best path to destination networks9.Refer to the exhibit. What does JAX do with link-state packets from ORL? sends out its updated routing table to both ORL and BOS routerssends out the individual link-state packets out the interface connected to BOSqueries BOS to see if it has a better routeonly adds it to the local routing table and performs no other actions10. What two statements correctly describe the link state routing process? (Choose two.)each router in the area floods LSPs to all neighborsall routers in the area have identical link state databasesLSPs use the reserved multicast address of 224.0.0.10 to reach neighbors routing loops are prevented by running the Diffusing Update Algorithm (DUAL)Reliable Transport Protocol (RTP) is the protocol used by for the delivery and reception of LSPs11. Which database or table must be identical on all link-state routers within an area in order to construct an accurate SPF tree?routing tableadjacency tablelink-state databaseneighbor tabletopology database12.Refer to the exhibit. Which statement correctly describes the path traffic would take from the 10.0.0.0/24 network to the 192.168.1.0/24 network if a link-state routing protocol was in use?BOS -> ATL because this path is the least hopsBOS -> ATL because this path is highest costBOS -> ORL -> JAX -> ATL because this path is the lowest costtraffic would load balance across all links13. What feature do modern link-state protocols provide to minimize processing and memory requirements?splitting routing topologies into smaller areasassigning lower process priorities to route calculationsusing update timers to restrict routing updatesstrict split horizon rules to reduce routing table entries14. What speeds up convergence in a network using link-state routing? updates triggered by network changesupdates sent at regular intervalsupdates sent only to directly connected neighborsupdates that include complete routing tables15. Which algorithm is run by link-state routing protocols to calculate the shortest path to destination networks?DUALDijkstraBellman-FordDiffie-Hellman16. What are some of the advantages of using a link-state routing protocol instead of a distance vector routing protocol? (Choose two.)The topology database eliminates the need for a routing table.Frequent periodic updates are sent to minimize the number of incorrect routes in the topological database.Routers have direct knowledge of all links in the network and how they are connected.After the inital LSA flooding, they generally require less bandwidth to communicate changes in a topology.Link-state protocols require less router processor power than distance vector protocols.17.Refer to the exhibit. If all routers and interfaces are configured to use a link-state routing protocol, from which routers will router D receive hello packets?A and EB and CA, B, C, and EC only18. Which two routing protocols use Dijkstra’s shortest path first algorithm? (Choose two.)RIPv1RIPv2IS-ISBGPEIGRPOSPF19. When are link-state packets sent to neighbors?every 30 secondsevery 180 secondsafter the holddown time expireswhen a link goes up or downwhen a routing loop occurs20. What are two advantages of using a link-state routing protocol instead of a distance vector routing protocol? (Choose two.)The topology database eliminates the need for a routing table.Each router independently determines the route to each network.Link-state protocols require less router processor power than distance vector protocols.After the inital LSP flooding, they generally require less bandwidth to communicate changes in a topology.Frequent periodic updates are sent to minimize the number of incorrect routes in the topological database.21. To achieve network convergence, what three steps does each link state router take? (Choose three.)use automatic summarization to reduce the size of routing tables build a Link State Packet (LSP) containing the state of each directly connected linkflood the LSP to all neighbors, who then store all LSPs received in a databasesend hello packages at regular intervals to discover neighbors and establish adjacenciesconstruct a complete map of the topology and compute the best path to each destination networkuse the DUAL FSM to select efficient, loop-free paths, and insert routes into the routing table。

诶了我累了目录第二章网络通信P2-8第三章应用层功能及协议P9-14 第四章 OSI 传输层 P15-20第五章 OSI 网络层 P21-27第六章网络编址-IPv4 P28-34第七章数据链路层P35-40第八章 OSI 物理层 P41-45第九章以太网P46-51第十章网络规划和布线P52-61 第十一章配置和测试网络P62-70 第一学期末考试P71-91文档末尾返回目录第二章网络通信001 TCP/IP 网络接入层有何作用路径确定和数据包交换数据表示、编码和控制可靠性、流量控制和错误检测详细规定构成物理链路的组件及其接入方法将数据段划分为数据包2下列哪些陈述正确指出了中间设备在网络中的作用（选择三项）确定数据传输路径发起数据通信重新定时和重新传输数据信号发送数据流管理数据流数据流最后的终止点003 下列哪三项陈述是对局域网(LAN) 最准确的描述（选择三项）LAN 通常位于一个地域内。

此类网络由由一个组织管理。

LAN 中的不同网段之间一般通过租用连接的方式连接。

此类网络的安全和访问控制由服务提供商控制。

LAN 为同一个组织内的用户提供网络服务和应用程序访问。

此类网络的每个终端通常都连接到电信服务提供商(TSP)。

004 什么是PDU传输期间的帧损坏在目的设备上重组的数据因通信丢失而重新传输的数据包特定层的封装005 OSI 模型哪两层的功能与TCP/IP 模型的网络接入层相同（选择两项）网络层传输层物理层数据链路层会话层6请参见图示。

所示网络属于哪一类型WANMANLANWLAN7以下哪种特征正确代表了网络中的终端设备管理数据流发送数据流重新定时和重新传输数据信号确定数据传输路径008 第 4 层端口指定的主要作用是什么标识本地介质中的设备标识源设备和目的设备之间的跳数向中间设备标识通过该网络的最佳路径标识正在通信的源终端设备和目的终端设备标识终端设备内正在通信的进程或服务9请参见图示。

这是我学习过程中遇见的ccna试题，中文一份，英文一份，很经典呀。

1 技术人员需要为某幢已经布设有线以太网络的大厦提供无线连接。

哪三个因素会影响需要的接入点数目？（选择三项。

）大厦的规模大厦中实体内墙的数目多个办公室中有微波炉无线网络中使用的加密方法Windows 和Appletalk 操作系统的同时使用AP 中短波或红外线的使用2 下列关于无线网桥的陈述，哪一项是正确的？通过无线链路连接两个网络连接无线局域网的固定设备允许无线客户端连接到有线网络增强无线信号的强度3 接入点默认使用哪一类身份验证？开放式PSKWEPEAP4请参见图示。

在Linksys 集成路由器的Wireless 菜单选项中，Network Mode 选项Mixed 是什么意思？路由器支持加密和身份验证。

路由器支持有线和无线两种连接。

路由器支持802.11b、802.11g 和802.11n 设备。

路由器支持通过红外和无线电射频连接。

5 接入点可以使用哪两种身份验证方法？（选择两项。

）WEPWPAEAPASCII预共享密钥6 哪项接入点功能允许网络管理员定义可以进入无线网络的数据类型？加密黑客攻击拦截通信过滤MAC 地址过滤身份验证7 下列关于服务集标识符(SSID) 的陈述中，哪两个是正确的？（选择两项。

）标识无线设备所属的WLAN是一个包含32 个字符的字符串，不区分大小写负责确定信号强度同一WLAN 中的所有无线设备必须具有相同的SSID用于加密通过无线网络发送的数据8请参见图示。

在Linksys 集成路由器的Wireless 菜单中，哪个配置选项可用于让附近的客户端知道接入点的存在。

Network ModeNetwork Name (SSID)Radio BandWide ChannelStandard ChannelSSID Broadcast9 下列哪个术语准确描述了为防止黑客读取截取到的数据而进行的无线数据编码？地址过滤身份验证广播加密密码短语编码10 两种WEP 密钥长度分别是多少？（选择两项。

以下是针对您未获得满分的试题给出的反馈。

某些交互式试题可能不显示您的答案。

分项分数：1哪个接口是包含用于管理24 个端口以太网交换机的IP 地址的默认位置？正确响应您的响应VLAN 1Fa0/0Fa0/1连接到默认网关的接口VLAN 99此试题参考以下领域的内容：Routing and Switching Essentials• 2.1.1 使用初始设置配置交换机2下列关于使用全双工快速以太网的陈述中，哪三项是正确的？（请选择三项。

）正确响应您的响应通过双向数据流改善了性能。

由于禁用了设备上的冲突检测功能，因此性能得到了改善。

节点以全双工单向数据流运行。

由于网卡可以检测到冲突，因此性能得到了改善。

全双工快速以太网在两个方向上提供100% 的效率。

由于网卡能更快速地处理帧，因此延迟减少了。

此试题参考以下领域的内容：Routing and Switching Essentials• 2.1.2 配置交换机端口3使用mdix auto 配置命令会对交换机上的以太网接口产生什么影响？正确响应您的响应自动检测双工设置自动检测接口速度自动检测铜电缆类型自动将第一个检测到的MAC 地址分配给接口此试题参考以下领域的内容：Routing and Switching Essentials• 2.1.2 配置交换机端口4在Cisco IOS 软件无法加载的情况下，网络管理员需要哪种类型的电缆将PC 与交换机连接才能恢复它？正确响应您的响应同轴电缆控制台电缆交叉电缆直通电缆因为交换机上没有运行Cisco IOS 软件，所以管理员需要使用控制台电缆将PC 连接到交换机控制台端口，比便将来自PC 的软件转移到交换机。

此试题参考以下领域的内容：Routing and Switching Essentials• 2.1.1 使用初始设置配置交换机5在对连接问题进行故障排除时，网络管理员发现交换机端口状态LED 在绿色和琥珀色之间跳转。

培训大讲堂官方YY 频道：3660mCCNA题库考试代号： 640-802考试时间：英文110+30=140分钟通过分数： 825题库版本： V104.4鸿鹄论坛招募CCNA、CCNP答疑讲师答疑地点：鸿鹄官方YY频道3660鸿鹄大讲堂：bbs.hh010./thread-46172-1-1.htmlCCNA题库战报交流QQ群：144288127 （500人超级群）CCNA题库战报交流区： bbs.hh010./forum-261-1.html1000 G视频教程免费下载：bbs.hh010./forum-228-1.htmlCCNA（640-802）题库V104.4CCNA（640-802）题库V104.4（情人节版）CCNA 题库战报500人超级QQ群 144288127V104系列是官方的终结版本，以后不会再出V105 V106 V108等等CCNA 最新题库/最新战报发布区： bbs.hh010./forum-261-1.html下载官方正版题库、看最新考试战报，请随时关注鸿鹄论坛 bbs.hh010.CCNA考试报名1900，详情请联系鸿鹄全国区十七名客服 QQ 71202306========================================更新容：V104.1修正V104中错误题目，确定经典争议题目答案；V104.2增加拖图题并可完美模拟考试，VCE题库增加中文注释；V104.3针对思科CCNA考试变题，更新考试新增题目93Q,更新V104.2实验题；V104.4增加全文中文注释，汇总V104.3九次更新，删除部分旧题目，为目前最新官方正版题库；2011.8.1 增加每日新题，修订部分错误。

2012.2.14 情人节版增加5道新题，分别是519、520、521、522、523题修改176题、375题、443题、482题答案错误修改59题、88题、453题、107题、270题注释错误增加个别疑难拖图题注释，优化实验题=============================================QUESTION 1When you are logged into a switch, which prompt indicates that you are in privileged mode?(当您登录到交换机，哪种提示表明你在特权模式？)A. %B.C. >D. $E. #Answer: ESection: Chapter 4: Introduction to Cisco IOSExplanation/Reference:特权模式就是#提示符QUESTION 2Which command shows system hardware and software version information?(哪些命令显示系统硬件和软件的版本信息？)A. show configurationB. show environmentC. show inventoryD. show platformE. show versionAnswer: ESection: Chapter 4: Introduction to Cisco IOSExplanation/Reference:查看系统的软件和硬件信息使用的命令是show versionQUESTION 3Cisco Catalyst switches CAT1 and CAT2 have a connection between them using ports FA0/13. An 802. 1Q trunk is configured between the two switches. On CAT1, VLAN 10 is chosen as native, but on CAT2 the native VLAN is not specified.What will happen in this scenario?(思科 Catalyst 交换机 CAT1 和 CAT2 有它们之间的连接使用端口FA0/13。

第五章 RIPv1 CCNA2 Exploration: 路由协议和概念(2019-12-15 18:07:13)转载▼标签：杂谈分类： 2010｜CCNA2官方试题--路由1 窗体顶端ERouting Chapter 7 - CCNA Exploration: 路由协议和概念(版本 4.0)以下行显示在 show ip route 命令的输出中。

R 192.168.3.0/24 [120/3] via 192.168.2.2, 00:00:30, Serial0/0该路由度量的值是什么？3122030120 窗体底端2 窗体顶端下列关于 RIPv1 特性的陈述中，哪两项是正确的？（选择两项。

）它是一种距离矢量路由协议。

它会在路由更新中通告路由的地址和子网掩码。

RIP 消息的数据部分封装在 TCP 数据段中。

RIP 消息的数据部分封装在 UDP 数据段中。

它每 15 秒广播一次更新。

它最多允许路由域中存在 15 台路由器。

窗体底端3 窗体顶端请参见图示。

图中所示的网络运行 RIPv1。

不久前其中添加了192.168.10.0/24 网络，该网络将只包含最终用户。

如果要防止向新网络中的最终用户设备发送 RIPv1 更新，同时允许将此新网络通告给其它路由器，应该在 Router1 上输入什么命令？Router1(config-router)# no router ripRouter1(config-router)# network 192.168.10.0Router1(config-router)# no network 192.168.10.0Router1(config-router)# passive-interface fastethernet 0/0Router1(config-router)# passive-interface serial 0/0/0窗体底端4 窗体顶端请参见图示。

••试题反馈报告IntroductiontoNetworks(版本-ITN第3章考试以下是针对您未获得满分的试题给出的反馈。

某些交互式试题可能不显示您的答案。

分项分数：1两台计算机可以使用什么方法来确保数据包不会因为过多数据发送过快而被丢弃？正确响应您的响应封装访问方法流量控制响应超时为使两台计算机能够有效通信，必须具有让源和目标设置数据传输和接收时间的机制。

为了正确接收数据，流量控制可以确保数据不会发送的太快。

此试题参考以下领域的内容：IntroductiontoNetworks•规则2哪种类型的通信会向局域网上的所有设备发送消息？正确响应您的响应广播单播组播全播广播通信是一对所有的通信。

单播通信是一对一的通信。

组播是一对多的通信，其中消息会发送给一组特定主机。

全播不是一个描述消息传输的标准术语。

此试题参考以下领域的内容：IntroductiontoNetworks•规则3哪个过程用于将一个消息放入另一消息内以从源传输到目的地？正确响应您的响应流量控制封装访问控制解码封装是将一种消息格式放入另一种消息格式的过程。

例如，一个数据包在封装成帧时如何将其完整放入数据字段中。

此试题参考以下领域的内容：IntroductiontoNetworks•规则4Web客户端向Web服务器发送一个网页请求。

从客户端的角度来讲，用于准备传输请求的协议栈正确顺序是什么？正确响应您的响应HTTP、TCP、IP、以太网HTTP、IP、TCP、以太网以太网、TCP、IP、HTTP以太网、IP、TCP、HTTP用于控制Web服务器和客户端进行交互的方式。

用于管理Web服务器与客户端之间的每次会话。

负责通过最佳路径传输到目标。

4.以太网从IP获取数据包，并将其格式化以供传输。

此试题参考以下领域的内容：IntroductiontoNetworks•协议5下列有关网络协议的陈述哪项是正确的？正确响应您的响应只有在远程网络中的设备之间交换消息时才需要使用网络协议。

1请参见图示。

“O*E2 0.0.0.0/0 [110/1] via 192.168.1.1, 00:05:34, Serial0/0”一行中的“O*6”代表什么含义？4Refer to the exhibit. What does the "O*E2" from the "O*E2 0.0.0.0/0 [110/1] via 192.168.1.1, 00:05:34, Serial0/0" line represent?内部第2类OSPF路由。

an internal type 2 OSPF route.距离至少两跳远的外部OSPF路由。

an external OSPF route at least two hops away. 来自两个不同源的外部OSPF路由。

an external OSPF route from two different sources. 不会增加开销的外部OSPF路由。

an external OSPF route that will not increment in cost.默认路由。

a default route.该路由是从第2类路由器分布到OSPF的。

The route was distributed into OSPF from a type 2 router.2请参见图示。

到10.0.0.0网络的路由的开销是多少？3Refer to the exhibit. What is the cost of the route to the 10.0.0.0 network?211017861.5443、为形成邻接关系，OSPF路由器之间的哪三项参数必须相等？（选择三项。

）145What three parameters must be indentical between OSPF routers in order to form an adjacency? 区域id area idK-values K-values度量值metric valuehello间隔hello interval网络类型network type接口类型interface type4、在存在大量邻居的网络中，OSPF会使用什么来减少路由信息的交换次数？（选择两项。

c c n a第二学期练习答案(总45页)--本页仅作为文档封面，使用时请直接删除即可----内页可以根据需求调整合适字体及大小--ERouting Chapter 1 - CCNA Exploration: 路由协议和概念(版本1口令可用于限制对 Cisco IOS 所有或部分内容的访问。

请选择可以用口令保护的模式和接口。

（选择三项。

）VTY 接口控制台接口特权执行模式2路由器从相连的以太网接口收到消息后，会更改哪项报头地址，再将消息从另一个接口发送出去第 2 层源地址和目的地址3请参见图示。

网络管理员已经为路由器连接到直连网络的接口配置了如图所示的 IP 地址。

从路由器 ping 相连网络路由器接口之间相互 ping 都会遭到失败。

此问题最可能的原因是什么必须使用no shutdown命令启用接口。

4请参见图示。

主机 A ping 主机 B。

当 R 网接口的 ping 时，哪两块报头信息包括在内（选择两项。

）目的 IP 地址：目的 MAC 地址：5网络管理员刚把新配置输入 Router1。

要将配置更改保存到 NVRAM，应该执行哪一条命令Router1# copy running-config startup-config6您需要配置图中所示的串行连接，必须在 Sydney 路由下哪条配置命令才能与 Melbourne 站点建立连接（选择三项）Sydney(config-if)# ip addressSydney(config-if)# no shutdownSydney(config-if)# clock rate 560007请参见图示。

从路由器的运行配置输出可得出什么结论显示的命令决定了路由器的当前运行情况。

8请参见图示。

在主机 2 连接到 LAN 上的交换机后，主主机 1 通信。

导致此问题的原因是什么主机 1 和主机 2 位于不同的网络中。

9输入以下命令的作用是什么？R1(config)# line vty 0 4R1(config-line)# password check123R1(config-line)# login设置通过 Telnet 连接该路由器时使用的口令10以下哪一项正确描述了路由器启动时的顺序加载 bootstrap、加载 IOS、应用配置11加载配置文件时的默认顺序是怎样的NVRAM、TFTP、CONSOLE12请参见图示。

1关于数据包通过路由器传输时的封装和解封的表达，以下哪三项是正确的？〔选择三项。

〕路由器修改 TTL 字段，将其值减 1。

路由器将源 IP 更改为送出接口的 IP。

路由器保持一样的源 IP 和目的 IP。

路由器将源物理地址更改为送出接口的物理地址。

路由器将目的 IP 更改为送出接口的 IP。

路由器会从所有接口将数据包转发出去，包括路由器接收数据包时使用的那个接口。

Option 1, Option 3, and Option 4 are correct.2请参见图示。

当数据包发往哪两个网络时需要路由器执行递归查找？〔选择两项。

〕Option 1 and Option 6 are correct.3对于为防止路由环路而通过毒性反转实现的水平分割方法，哪两项表达正确？〔选择两项。

〕所有 Cisco IOS 都会默认启用此方法。

会将一个表示无穷大度量的值分配给路由以将其毒化。

将毒化路由更新发回该更新的发送接口。

指示路由器将可能会影响路由的更改保持一段特定的时间。

限制数据包在被丢弃之前能够在网络中传输的跳数。

Option 2 and Option 3 are correct.4网络管理员在所示网络图中的路由器 B 和 C 上启用了 RIP。

什么命令可防止向路由器 A 发送 RIP 更新？A(config)# router ripA(config-router)# passive-interface S0/0B(config)# router ripA(config)# router ripB(config)# router ripB(config-router)# passive-interface S0/0A(config)# no router rip2 points for Option 45请参见图示。

根据如下列图的输出，以下哪两项陈述是正确的？〔选择两项。

〕所有路由都处于稳定状态。

每条路由都有一个可行后继。

思科c c n a第11章测试1此试题参考以下领域的内容：Introduction to Networks•11.1.1 小型网络中的设备2 哪种协议支持流媒体的快正确响应您的响应SNMPTCPPoERTPSNMP 是一种管理协议。

TCP 不适而是允许以太网电缆为设备输送电源此试题参考以下领域的内容：Introduction to Networks•11.1.2 小型网络中的协议3 如何捕获流量才能更好地了解网络中的流量模式？正确响应您的响应在利用率较低时在利用率高峰期当流量仅在主干网段上当流量来自用户子集时在利用率较低时捕获流量无法获得不同流量类型的正确表示。

由于某些流量可能局限于特定网捕获流量。

此试题参考以下领域的内容：Introduction to Networks•11.1.3 发展为大型网络4 网络管理员检查安全日志，发现周末有人未经授权访问了一个器。

经过仔细调查文件系统日志，管理员注意到几个重要文档部的主机。

这种情况代表哪种威胁？正确响应您的响应数据丢失身份盗窃信息盗窃服务中断信息盗窃威胁是指公司的内部信息被未授权的用户访问和复制。

此试题参考以下领域的内容：Introduction to Networks•11.2.1 网络设备安全措施5 下列哪两项操作可以防止他人成功攻击电子邮件服务器帐户？（正确响应您的响应不要通过网络以明文形式发送密码。

不要使用需要Shift 键的密码。

不要允许服务器控制台的物理访问。

仅允许授权人员访问服务器机房。

限制登录到服务器的失败尝试次数。

最常见的一种访问攻击类型是利用数据包嗅探器来获取以明文形式传输的用户帐户和密码。

反进行未经授权的访问，属于另一种访问攻击。

限制尝试登录到服务器的次数并使用加密密码，攻击类型成功登录。

此试题参考以下领域的内容：Introduction to Networks•11.2.2 漏洞和网络攻击6 下列哪种网络攻击会导致网络、系统或服务的禁用或损坏？正确响应您的响应侦察攻击访问攻击拒绝服务攻击恶意代码攻击拒绝服务攻击是指网络、系统或服务被禁用或损坏。

交换测试题目1.以下关于以太网交换机交换方式的叙述中，哪些是正确的？(多选)A.Store and Forward 方式不能检测出超短帧（<64 字节）B.Cut-through 方式交换时，交换机不对以太网帧进行过滤C.使用Cut-through 方式，以太网帧将不会在交换机中作任何存储D.Store and Forward 方式交换时，交换机将对以太网帧进行逐个过滤ANSWER:B C D2.IEEE 802.3 以太网采用什么协议以支持总线性结构，它的全称是什么？A.STP，Spanning Tree ProtocolB.STP，Shortest Tree ProtocolC.CSMA/CD Carrier Sense Multicast Access/Collision DetectionD.CSMA/CD Carrier Sent Multicast Access/CRC DetectionE.CSMA/CD Carrier Service Multiple Access/Collision DetectionF.CSMA/CD Carrier Sense Multiple Access/Collision DetectionANSWER:F3.VLAN tag 在OSI 参考模型的哪一层实现？A.物理层B.数据链路层C.网络层D.应用层ANSWER:B4.以太网交换机一个端口在接收到数据帧时，如果没有在MAC 地址表中查找到目的MAC 地址，通常如何处理A.把以太网帧复制到所有的端口B.把以太网帧单点传送到特定端口C.把以太网帧发送到除本端口以外的所有端口D.丢弃该帧E.把以太网帧发送到一组特定的端口ANSWER:C5.采用了什么协议的网络中，工作站在发送数据之前，要检查网络是否空闲，只有在网络不阻塞时，工作站才能发送数据？A.TCPB.IPC.ICMPD.CSMA/CDANSWER:D6.下列哪个协议允许VLAN的配置信息传播到其它新加入的交换网络？A. STPB. VTPC. EIGRPD. SNMPE. CDPF. None of the aboveAnswer: B7.下列哪个封装类型可以配置在一个Cisco交换机的trunk上？(选择两个)A. VTPB. ISLC. CDPD. 802.1QE. 802.1pF. LLCG. IETFAnswer: B, D8.当交换机的一个端口作为一个VLAN trunk, 下列哪一个trunk模式是有效的? (选择所有正确的)？A. BlockingB. AutoC. DesirableD. OnE. TransparentF. LearningAnswer: B, C, D9.下列哪一个模式可以在一台Cisco 交换机上创建或者删除VLANs 以便管理一个VLAN的域?A. TransparentB. ServerC. AutoD. ClientE. UserAnswer: B10.TestKing网络的结构如下图：网络中的所有主机和服务器都在相同的网络，根据上面的图，下面哪个描述是正确的?A. 交换机TestKing2是一个根桥B. 生成树协议没有被运行.C. 主机TestKingD 和Server1 在一个相同的网络中D. 没有冲突出现在主机TestKingB和主机TestKingC之间Answer: C11.根据上面Tesking1 交换机的输出信息.这个交换机VTP的功能是什么?A. 创建、修改、和删除VLANsB. 学习和保存VTP 配置信息只在running configuration 里C. 转发VTP 配置信息D. 备份一个VTP数据库为最近的VTP服务器E. 阻止VTP信息到达工作组的交换机Answer: C12.在以太网交换网络中有环路出现也能正常工作，则是由于运行了什么协议？A.801.zB.802.3C.TrunkD.Spanning TreeANSWER:D13.以太网中哪些设备可以将网络分成多个冲突域，但不能将网络分成多个广播域？(多选)A.网桥B.交换机C.路由器D.集线器ANSWER:A B14.以太网交换机的每一个端口都可以看做一个？A.冲突域B.广播域C.管理域D.阻塞域ANSWER:A15.MAC 子层有哪些功能？(多选)A.提供逻辑地址B.提供硬件地址C.提供流控功能D.对上层屏蔽下层传输介质ANSWER:B D16.LLC 子层有哪些功能？A.提供逻辑地址B.提供硬件地址C.提供流控功能D.对上层屏蔽下层传输介质ANSWER:C17.在以太网交换机中哪种转发方法延迟较小？A.全双工B.Cut-throughC.Store-and-forwardD.半双工ANSWER:B18.一台WINDOWS 机器启动时发出的广播包中其目的MAC 地址为？A.00000000B.11111111C.FFFFFFFFFFFFANSWER:C19.以下关于MAC 地址的说法中正确的是？(多选)A.MAC 地址的一部分字节是各个厂家从IEEE 得来的B.MAC 地址一共有6 个字节，他们从出厂时就被固化在网卡中C.MAC 地址也称做物理地址，或通常所说的计算机的硬件地址D.局域网中的计算机在判断所收到的广播帧是否为自己应该接收的方法是，判断帧的MAC 地址是否与本机的硬件地址相同ANSWER:A B C20.VLAN 的划分方法有哪些？(多选)A.基于设备的端口B.基于协议C.基于MAC 地址D.基于物理位置ANSWER:A B C21.关于共享式以太网说法正确的是？(多选)A.需要进行冲突检测B.仅能实现半双工流量控制C.利用CSMA/CD 介质访问机制ANSWER:A B C22.以下关于以太网交换机的说法哪些是正确的？A.以太网交换机是一种工作在网络层的设备B.以太网交换机最基本的工作原理就是802.1DC.生成树协议解决了以太网交换机组建虚拟局域网的需求D.使用以太网交换机可以隔离冲突域ANSWER:B D23.以下说法错误的是？A.桥能隔离网络层广播B.中继器是工作在物理层的设备C.路由器是工作在网络层的设备D.以太网交换机工作在数据链路层ANSWER:A24.目前，我国使用最广泛的LAN 标准是基于哪一个以太网标准？A.IEEE 802.1B.IEEE 802.2C.IEEE 802.3D.IEEE 802.5ANSWER:C25.本地网络上的主机通过下列所述的那种方式查找其它的网络设备？A.端口号B.硬件地址C.默认网关D.逻辑网络地址ANSWER:B26.为了扩大网络范围，可以使用什么设备连接多根电缆，放大信号？A.中继器B.HUBC.路由器D.网桥ANSWER:A27.请列出交换机系列网络产品实施虚拟局域网的优点。

1A network administrator is determining the best placement of VLAN trunk links. Which two types of point-to-point connections utilize VLAN trunking? (Choose two.)between two switches that share a common VLANbetween a switch and a server that has an 802.1Q NIC*between a switch and a client PCbetween a switch and a network printerbetween two switches that utilize multiple VLANs*2What happens to a port that is associated with VLAN 10 when the administrator deletes VLAN 10 from the switch?The port automatically associates itself with the native VLAN.The port creates the VLAN again.The port goes back to the default VLAN.The port becomes inactive.*3Refer to the exhibit. Interface Fa0/1 is connected to a PC. Fa0/2 is a trunk link to anotherswitch. All other ports are unused. Which security best practice did the administrator forget to configure?Configure all unused ports to a ‘black-hole’ VLAN that is not used for anything on the network.Disable autonegotiation and set ports to either static access or static trunk.Change the native VLAN to a fixed VLAN that is distinct from all user VLANs and to a VLAN number that is not VLAN 1.All user ports are associated with VLANs distinct from VLAN 1 and distinct from the‘black-hole’ VLAN.*4Which command is used to remove only VLAN 20 from a switch?no switchport access vlan 20delete flash:vlan.datno vlan 20*delete vlan.dat5A Cisco Catalyst switch has been added to support the use of multiple VLANs as part of an enterprise network. The network technician finds it necessary to clear all VLAN information from the switch in order to incorporate a new network design. What should the technician do to accomplish this task?Erase the startup configuration and reboot the switch.Erase the running configuration and reboot the switch.Delete the startup configuration and the vlan.dat file in the flash memory of the switch and reboot the switch.*Delete the IP address that is assigned to the management VLAN and reboot the switch.6What is the effect of issuing a switchport access vlan 20 command on the Fa0/18 port of a switch that does not have this VLAN in the VLAN database?VLAN 20 will be created automatically.*The command will have no effect on the switch.Port Fa0/18 will be shut down.An error stating that VLAN 20 does not exist will be displayed and VLAN 20 is not created. 7Which command displays the encapsulation type, the voice VLAN ID, and the access mode VLAN for the Fa0/1 interface?show mac address-table interface Fa0/1show interfaces Fa0/1 switchport*show interfaces trunkshow vlan brief8Place the options in the following order:- not scored -dynamic autononegotiatedynamic desirabletrunk9Port Fa0/11 on a switch is assigned to VLAN 30. If the command no switchport access vlan 30 is entered on the Fa0/11 interface, what will happen?Port Fa0/11 will be returned to VLAN 1.*VLAN 30 will be deleted.An error message would be displayed.Port Fa0/11 will be shutdown.10What must the network administrator do to remove Fast Ethernet port fa0/1 from VLAN 2 and assign it to VLAN 3?Enter the no vlan 2 and the vlan 3 commands in global configuration mode.Enter the switchport trunk native vlan 3 command in interface configuration mode.Enter the switchport access vlan 3 command in interface configuration mode.*Enter the no shutdown in interface configuration mode to return it to the default configuration and then configure the port for VLAN 3.11Which two Layer 2 security best practices would help prevent VLAN hopping attacks? (Choose two.)Disable DTP autonegotiation on end-user ports.*Change the management VLAN to a distinct VLAN that is not accessible by regular users.Statically configure all ports that connect to end-user host devices to be in trunk mode. Change the native VLAN number to one that is distinct from all user VLANs and is not VLAN 1.*Use SSH for all remote management access.12In a basic VLAN hopping attack, which switch feature do attackers take advantage of?automatic encapsulation negotiationthe default automatic trunking configuration*an open Telnet connectionforwarding of broadcasts13A Cisco switch currently allows traffic tagged with VLANs 10 and 20 across trunk port Fa0/5. What is the effect of issuing a switchport trunk allowed vlan 30 command on Fa0/5?It allows only VLAN 30 on Fa0/5.*It allows a native VLAN of 30 to be implemented on Fa0/5.It allows VLANs 1 to 30 on Fa0/5.It allows VLANs 10, 20, and 30 on Fa0/5.14Refer to the exhibit. A frame is traveling between PC-A and PC-B through the switch. Which statement is true concerning VLAN tagging of the frame?No VLAN tag is added to the frame.*A VLAN tag is added when the frame is accepted by the switch.A VLAN tag is added when the frame is forwarded out the port to PC-B.A VLAN tag is added when the frame leaves PC-A.15Refer to the exhibit. PC-A and PC-B are both in VLAN 60. PC-A is unable to communicate with PC-B. What is the problem?The native VLAN is being pruned from the link.The VLAN that is used by PC-A is not in the list of allowed VLANs on the trunk.*The trunk has been configured with the switchport nonegotiate command.The native VLAN should be VLAN 60.16What VLANs are allowed across a trunk when the range of allowed VLANs is set to the default value?All VLANs will be allowed across the trunk.*Only the native VLAN will be allowed across the trunk.The switches will negotiate via VTP which VLANs to allow across the trunk.Only VLAN 1 will be allowed across the trunk.17Under which two occasions should an administrator disable DTP while managing a local area network? (Choose two.)on links that should not be trunking*when connecting a Cisco switch to a non-Cisco switch*on links that should dynamically attempt trunkingwhen a neighbor switch uses a DTP mode of dynamic autowhen a neighbor switch uses a DTP mode of dynamic desirable18Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.Which PCs will receive the broadcast sent by PC-C?PC-D, PC-E*PC-A, PC-B, PC-D, PC-EPC-A, PC-BPC-A, PC-B, PC-D, PC-E, PC-FPC-A, PC-B, PC-E19Which two statements are true about VLAN implementation? (Choose two.)The network load increases significantly because of added trunking information.Devices in one VLAN do not hear the broadcasts from devices in another VLAN.*The size of the collision domain is reduced.VLANs logically group hosts, regardless of physical location.*The number of required switches in a network decreases.20Refer to the exhibit. DLS1 is connected to another switch, DLS2, via a trunk link. A host that is connected to DLS1 is not able to communicate to a host that is connected to DLS2, even though they are both in VLAN 99. Which command should be added to Fa0/1 on DLS1 to correct the problem?switchport trunk allowed vlan add 99switchport trunk native vlan 66*switchport mode dynamic autoswitchport nonegotiate21Which switch feature ensures that no unicast, multicast, or broadcast traffic is passed between ports that are configured with this feature?switch port securityPVLAN protected port*ACLVLAN22Fill in the blank. Use the full command syntax.The ” show vlan brief” command displays the VLAN assignment for all ports as well as the existing VLANs on the switch.23Which three statements accurately describe VLAN types? (Choose three).An 802.1Q trunk port, with a native VLAN assigned, supports both tagged and untagged traffic.*A management VLAN is any VLAN that is configured to access management features of the switch.* A data VLAN is used to carry VLAN management data and user-generated traffic.Voice VLANs are used to support user phone and e-mail traffic on a network.VLAN 1 is always used as the management VLAN.After the initial boot of an unconfigured switch, all ports are members of the default VLAN.* 24Which command should the network administrator implement to prevent the transfer of DTP frames between a Cisco switch and a non-Cisco switch?S1(config-if)# switchport mode trunkS1(config-if)# switchport mode accessS1(config-if)# switchport nonegotiate*S1(config-if)# switchport mode dynamic desirableS1(config-if)# switchport trunk allowed vlan none。

CCNA考试题库中英文翻译版及答案1[1]1. What are two reasons that a network administrator would use access lists? (Choose two.)1.出于哪两种理由，会使用访问列表?A. to control vty access into a routerA.控制通过VTY访问器B. to control broadcast traffic through a routerB.控制广播流量穿越路由器2.一个默认的帧中继WAN被分类为哪种物理网络类型?A. point-to-pointA.点到点B. broadcast multi-accessB.广播多路访问C. nonbroadcast multi-accessC.非广播多路访问D. nonbroadcast multipointD.非广播多点E. broadcast point-to-multipointE.广播点到多点Answer: C3. A single 802.11g access point has been configured and installed in the center of a squarA few wireless users are experiencing slow performance and drops while most users are oat peak efficiency. What are three likely causes of this problem? (Choose three.)3.一个802.11接入点被部署在一个方形办公室的中央，当大多数用户在大流量传输数一些用户发现无线网络变得缓慢和出现丢包A. mismatched TKIP encryptionB. null SSIDC. cordless phonesD. mismatched SSIDE. metal file cabinetsF. antenna type or directionAnswer: CEF4. Refer to the exhibit. How many broadcast domains exist in the exhibited topology?根据下图，图中的拓扑中存在多少个广播域?A. one A.1B. two B.2C. three C.3D. four D.4E. five E.5F. six F.6Answer: C5. Refer to the exhibit. What two facts can be determined from the WLAN diagram? (Choose two.)5.根据下图，WLAN diagram决定了哪两个事实A. The area of overlap of the two cells represents a basic service set (BSS).A. 两个 cells的overlap的区域描述了一个basic service setB. The network diagram represents an extended service set (ESS).B. 网络描述了一个extended service setC. Access points in each cell must be configured to use channel 1.C. 再每个CELL中的AP必须被配置成使用channel 1D. The area of overlap must be less than 10% of the area to ensure connectivity.D. 为了确保连通性,重叠区域必须小于10%E. The two APs should be configured to operate on different channels.E. 两个访问点应该被配置成工作在不同的频道Answer: BE6. The command frame-relay map ip 10.121.16.8 102 broadcast was entered on the router.Which of the following statements is true concerning this command?6.器上输入命令frame-relay map ip 10.121.16.8 102 broadcast，以下选项正确的是?A. This command should be executed from the global configuration mode.A.该命令应该在全局配置模式下被执行B. The IP address 10.121.16.8 is the local router port used to forward data.B.IP地址10.121.16.8是本地路由器用来转发数据的接口C. 102 is the remote DLCI that will receive the information.C.102是远端的DLCI它将接受信息。

第2章 配置网络操作系统1 下列哪两项是闪存的特征？（请选择两项。

）闪存提供非易失性存储。

当设备启动时，闪存接收来自 RAM 的 IOS 副本。

重新启动时闪存中的内容可能会丢失。

闪存是思科交换机的组件，但不是思科路由器的组件。

闪存的内容可以被覆盖。

当设备启动时，闪存会保存 IOS ，并将 IOS 副本传输到 RAM 中。

尽管闪存可以升级和覆盖，但它是非易失性存储器。

设备重新启动或断开电源时，闪存内容仍会保留。

答案 说明 最高分值correctness of response Option 1 and Option 5 are correct.1 point for each correct option. 0 points if more options are selected than required.22 网络管理员计划在总部的几个路由器和交换机上升级 IOS 。

继续选择和升级 IOS 之前必须回答哪三个问题？（请选择三项。

）设备是否位于同一 LAN ？设备是否有足够的 NVRAM 来存储 IOS 映像？什么型号的路由器和交换机需要升级？路由器和交换机上安装了哪些端口？路由器和交换机是否有足够的 RAM 和闪存来用于提议的 IOS 版本？设备需要哪些功能？启动配置文件存储在 NVRAM 中，而不是 IOS 中。

升级到新 IOS 版本时应考虑的重要因素包括可用 RAM 和闪存数量、设备类型和型号以及所需功能。

答案 说明 最高分值correctness of response Option 3, Option 5, and Option 6 are correct.1 point for each correct option. 0 points if more options are selected than required.33 当在安全环境下执行初始配置时，下列哪个程序可用来访问 Cisco 2960 交换机？使用 Telnet 通过网络远程访问交换机。

最新CCNA认证试题及答案「中文版」1、对于这样一个地址,192.168.19.255/20,下列说法正确的是: ( )(A) 这是一个广播地址(B) 这是一个网络地址(C) 这是一个私有地址(D) 地址在192.168.19.0网段上(E) 地址在192.168.16.0网段上(F) 这是一个公有地址答案：CE注：IP地址中关键是看她的主机位，将子网掩码划为二进制，1对应上面的地址是网络位，0对应的地址是主机位192.168.19.255/20划为二进制为：11000000.10101000.00010011.1111111111111111.11111111.11110000.00000000主机位变成全0表示这个IP的网络地址主机槐涑扇?表示这个IP的广播地址RFC1918文件规定了保留作为局域网使用的私有地址：10.0.0.0 - 10.255.255.255 (10/8 prefix)172.16.0.0 - 172.31.255.255 (172.16/12 prefix)192.168.0.0 - 192.168.255.255 (192.168/16 prefix)2、目前，我国应用最为广泛的LAN标准是基于()的以太网标准.(A) IEEE 802.1(B) IEEE 802.2(C) IEEE 802.3(D) IEEE 802.5答案：C参考知识点：现有标准：IEEE 802.1 局域网协议高层IEEE 802.2 逻辑链路控制IEEE 802.3 以太网IEEE 802.4 令牌总线IEEE 802.5 令牌环IEEE 802.8 FDDIIEEE 802.11 无线局域网记住IEEE802.1-------IEEE802.5的定义以太网是一种计算机局域网组网技术。

IEEE制定的IEEE 802.3标准给出了以太网的技术标准。

它规定了包括物理层的连线、电信号和介质访问层协议的内容。

第一章：正确答案：2.4.5解析：由于不需要使用网络设备和专用服务器，对等网络易于创建，复杂性更低，且成本更少。

而且对等网络也没有集中管理。

这种网络安全性更低，不可扩展，而且那些同时充当客户端和服务器的设备可能性能更差正确答案：1解析：正确答案： 3.5解析：选择网络介质的条件包括：所选介质可以成功传送信号的距离、要安装所选介质的环境、必须传输的数据量和速度以及介质和安装的成本。

正确答案：3和4解析：终端设备上的应用程序可以生成数据，更改数据内容并且负责启动封装过程。

正确答案：1和4解析：终端设备会发出通过网络传输的数据。

中间设备会在链路发生故障时通过备用路径传输数据，并且会过滤数据传输以增强安全性。

网络介质提供网络消息的传输通道。

正确答案：4解析：外联网是公司外部的人或企业合作伙伴访问数据的网络区域。

内部网只描述通常仅供内部人员访问的网络区域。

当设备连接到有线网络时，有线 LAN 会受 BYOD（自带设备）影响。

使用大学无线 LAN 的设备多为平板电脑和智能手机。

大学生主要使用无线 WAN 来访问他们的手机运营商网络。

.正确答案：2解析：由于通过 Internet 可以联系在线供应商，所以家庭用户通过 Internet 进行网上购物。

内联网基本上是仅供内部使用的局域网。

外联网是外部合作伙伴访问组织内部特定资源的网络。

家庭用户并不一定使用 LAN 来访问 Internet。

例如，PC 可以通过调制解调器直接连接到 ISP。

正确答案：1解析：内部网这个术语用于表示一个组织的私有局域网和广域网连接。

内部网的设计旨在仅允许该组织的成员、员工或其他获得授权的人员进行访问。

正确答案：2和4解析：电缆和 DSL 均能实现高带宽、始终联网，并提供到主机计算机或 LAN 的以太网连接。

10正确答案：2和3解析：移动电话连接需要使用移动电话网络。

卫星连接通常用于家庭或企业外部不便使用物理布线的位置。

11正确答案：2解析：当对网络资源的请求超出了可用容量时，网络就会变得拥堵。