6月份CCNA题库更新部分详解

CCNA认证试题一（附答案和解析）中文版(一)1、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。

以太网是当前应用最普遍的局域网技术。

它很大程度上取代了其他局域网标准，如令牌环、FDDI和ARCNET。

以太网的标准拓扑结构为总线型拓扑，但目前的快速以太网（100BASE-T、1000BASE-T标准）为了最大程度的减少冲突，最大程度的提高网络速度和使用效率，使用交换机（Switch）来进行网络连接和组织，这样，以太网的拓扑结构就成了星型，但在逻辑上，以太网仍然使用总线型拓扑的C***A/CD介质访问控制方法。

电气电子工程师协会或IEEE（Institute of Electrical and Electronics Engineers）是一个国际性的电子技术与信息科学工程师的协会。

建会于1963年1月1日。

总部在美国纽约市。

在150多个国家中它拥有300多个地方分会。

目前会员数是36万。

专业上它有35个专业学会和两个联合会。

IEEE发表多种杂志，学报，书籍和每年组织300多次专业会议。

IEEE定义的标准在工业界有极大的影响。

下面列出：IEEE802．3以太网标准802.3--------- 10Base以太网标准802.3u-------- 100Base-T（快速以太网）802.3z-------- 1000Base-X（光纤吉比特以太网）802.3ab-------- 1000Base-T（双绞线吉比特以太网）2、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)3、Quidway系列路由器在执行数据包转发时，下列哪些项没有发生变化（假定没有使用地址转换技术）？（）(A) 源端口号(B) 目的端口号(C) 源网络地址(D) 目的网络地址(E) 源MAC地址(F) 目的MAC地址答案：ABCD参考知识点：路由功能就是指选择一条从源网络到目的网络的路径，并进行数据包的转发。

完整版CCNA测试题库及答案描述载波侦听多路由访问/冲突检测（CSMA/CD）的工作原理。

CSMA/CD是一种帮助设备均衡共享带宽的协议，可避免两台设备同时在网络介质上传输数据。

虽然他不能消除冲突，但有助于极大的减少冲突，进而避免重传，从而提高所的设备的数据传输效率。

区分半双工和全双工通信。

并指出两种方法的需求。

与半双工以太网使用一对导线不同，全双工以太网使用两队导线，全双工使用不同的导线来消除冲突，从而允许同时发送和接收数据，而半双工可接收或发送数据，但不能同时接收和发送数据，且仍会出现冲突。

要使用全双工，电缆两端的设备都必须支持全双工，并配置成一全双模式运行。

描述MAC地址的组成部分以及各部分包含的信息。

MAC（硬件）地址时一种使用十六进制表示的地址，长48位（6B）。

其中前24位（3B）称为OUI（Organizationally Unique Idebtifier,组织唯一表示符），有IEEE分配给NIC制造商；余下的部分呢唯一地标识了NIC识别十进制数对应的二进制值和十六进制值。

用这三种格式之一表示的任何数字都可以转换为其他两种格式，能够执行这种转换对理解IP地址和子网划分至关重要。

识别以太网帧中与数据链路层相关的字段。

在以太网中，与数据链路层相关的字段包括前导码，帧其实位置分隔符，目标MAC地址，源MAC地址，长度或者类型以及帧校验序列。

识别以太网布线相关的IEEE标准。

这些标准描述了各种电缆类型的功能和物理特征，包括（但不限于）10Base2、10Base5和10BaseT。

区分以太网电缆类型及其用途。

以太网电缆分3种：直通电缆，用于将PC或路由器的以太网接口连接到集线器或交换机；交叉电缆。

用于将集线器连接到集线器，集线器连接到交换机，交换机连接到交换机以及PC连接到PC；反转电缆，用于PC和路由器或交换机之间建立控制台连接。

描述数据封装过程及其在分组创建中的作用。

数据封装指的是在OSI模型各层给数据添加信息的过程，也成为分组创建。

思科认证CCNA认证试题与答案中文版思科认证CCNA认证试题与答案中文版思科认证的考试内容包括笔试和实验。

笔试在全球认证的考试中心进行，时间为两个小时。

实验考试只限于思科在全世界范围内指定的6个考点，分别位于美国、澳大利亚、比利时、日本、北京的新世纪饭店以及香港。

实验室考试分为2天，第一天要求学生利用实验室提供的设备建立网络。

第二天由考官故意破坏学员的网络，学员则要想办法查出故障并加以解决。

下面是店铺为大家搜集的相关试题，供大家参考练习。

21、一个B类网络，有5位掩码加入缺省掩码用来划分子网，每个子网最多( )台主机(A) 510(B) 512(C) 1022(D) 2046答案：D22、在路由器中，能用以下命令察看路由器的路由表( )(A) arp -a(B) traceroute(C) route print(D) display ip routing-table答案：D23、DHCP客户端是使用地址( )来申请一个新的IP地址的(A) 0.0.0.0(B) 10.0.0.1(C) 127.0.0.1(D) 255.255.255.255答案：D注释:255.255.255.255是全网广播,DHCP客户端发送全网广播来查找DHCP服务器.24、下面有关NAT叙述正确的是( )(A) NAT是英文“地址转换”的缩写，又称地址翻译(B) NAT用来实现私有地址与公用网络地址之间的转换(C) 当内部网络的主机访问外部网络的时候，一定不需要NAT(D) 地址转换的.提出为解决IP地址紧张的问题提供了一个有效途径答案：ABD25、以下属于正确的主机的IP地址的是( )(A) 224.0.0.5(B) 127.32.5.62(C) 202.112.5.0(D) 162.111.111.111答案：D注释:这个题目不是太严谨,应该加上子网掩码.A:224.0.0.5是多播地址B:127.0.0.0保留作为测试使用C:网络地址26、设置主接口由up转down后延迟30秒切换到备份接口，主接口由down转up后60秒钟切换回主接口的配置为( )(A) standby timer 30 60(B) standby timer 60 30(C) standby timer enable-delay 60 disable-delay 30(D) standby timer enable-delay 30 disable-delay 60答案：D27、在一个以太网中，30台pc通过Quidway R2501路由器s0口连接internet，Quidway R2501路由器配置如下：[Quidway-Ethernet0]ip address 192.168.1.1 255.255.255.0 [Quidway-Ethernet0]quit[Quidway]interface s0[Quidway-Serial0]ip address 211.136.3.6 255.255.255.252[Quidway-Serial0]link-protocol ppp一台PC机默认网关为192.168.2.1,路由器会怎样处理发自这台PC 的数据包?(A) 路由器会认为发自这一台PC的数据包不在同一网段，不转发数据包(B) 路由器会自动修正这一台PC机的IP地址，转发数据包(C) 路由器丢弃数据包，这时候需要重启路由器，路由器自动修正误配(D) 路由器丢弃数据包，不做任何处理，需要重配PC网关为192.168.1.1答案：D注释:PC的默认网关要指向路由器的以太网口的IP地址.28、ISDN B信道速率是()(A) 16kbps(B) 64kbps(C) 144kbps(D) 2048kbps答案:B参考知识点：综合数字业务网(ISDN)由数字电话和数据传输服务两部分组成，一般由电话局提供这种服务。

最新版本CCNA考试第一章期末考试答案本文提供了最新版本的CCNA考试第一章期末考试答案，以供考生参考。

第一部分：单项选择题1. 以下哪种设备可用于实现广域网？A. 路由器B. 交换机C. 防火墙D. 网桥正解：A2. 哪一个网络层协议是用于将MAC地址转换为IP地址？A. ARP协议B. TCP协议C. UDP协议D. ICMP协议正解：A3. 网络安全中，以下哪项是确保数据在传输过程中不被窃取或修改的安全措施？A. 机密性B. 完整性C. 可用性D. 可验证性正解：B4. 在OSI模型中，下列哪层负责对收到的数据进行重新组装和排序？A. 传输层C. 数据链路层D. 物理层正解：A5. 哪种类型的地址可以用于从源到目的地的识别和路由？A. 物理地址B. MAC地址C. IP地址D. 逻辑地址正解：C第二部分：多项选择题1. 选择下列关于TCP传输协议的正确说法。

（可多选）A. TCP使用可靠性较低的UDP协议B. TCP的流控制指令有多种方式C. TCP在传输层实现D. TCP提供无连接服务正解：B、C2. 在主机间进行通信时，哪个MAC地址首先被使用？A. 源主机的MAC地址B. 目的主机的MAC地址C. 网关的MAC地址D. 路由器的MAC地址正解：C3. 下列哪个网络拓扑结构最好的容错性？A. 星形拓扑C. 总线型拓扑D. 带环形拓扑正解：A4. 以下哪个选项是网络安全的最佳实践？A. 使用复杂的密码并定期更改B. 允许所有用户访问系统C. 共享所有文件和文件夹D. 手动分配IP地址正解：A5. 哪种网络协议可以在发送方和接收方之间创建安全的数据连接？A. SSLB. HTTPC. FTPD. SMTP正解：A第三部分：简答题1. 请简要解释网络拓扑结构。

网络拓扑结构指的是计算机网络中设备的布局方式。

常见的网络拓扑包括星型、环状、总线型和带环型等。

其中，星型拓扑结构最为常见，它由多台计算机通过中心节点相连而组成。

•试题反馈报告Introduction to Networks (版本6.00) - ITN 第1 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某公司正在考虑是使用客户端/服务器还是对等网络。

下列哪三项是对等网络的特征？（选择三项。

）正确响应您的响应易于创建同时充当客户端和服务器时设备性能更好可扩展安全性提升缺少集中管理实施成本更少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。

此试题参考以下领域的内容：Introduction to Networks• 1.1.2 提供网络资源2哪种设备的功能是确定消息在网际网络中传输的路径？正确响应您的响应路由器防火墙Web 服务器DSL 调制解调器路由器用于确定消息在网络中的传输路径。

防火墙用于过滤传入和传出的流量。

DSL 调制解调器用于为家庭或组织提供Internet 连接。

此试题参考以下领域的内容：Introduction to Networks• 1.2.1 网络组件3哪两个条件有助于您从各种网络介质当中选择一种网络介质？（请选择两项。

）正确响应您的响应网络上使用的终端设备的成本所选介质可以成功传送信号的距离需要优先处理的数据类型安装在网络中的中间设备的数量要安装所选介质的环境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。

此试题参考以下领域的内容：Introduction to Networks• 1.2.1 网络组件4下列哪两项描述了中间设备？（选择两项。

）正确响应您的响应中间设备可以引导数据路径。

中间设备可以生成数据内容。

中间设备可以启动封装过程。

中间设备可以更改数据内容。

中间设备可以将单个主机连接到网络中。

学网络技术去鸿鹄网网络技术从零开始梦想之路鸿鹄开启鸿鹄论坛：鸿鹄团队致力于为每一位网络技术爱好者提供帮助有事您发帖，斑竹为您跑腿，给您答疑。

CCNA CCNP最新题库/最新战报发布区：/thread.php?fid-166.html 鸿鹄客服QQ:712023090请加QQ群：96564501103107466鸿鹄题库新纪元CCNA V102上卷（共上下两卷，加lab集）1What can a network administrator utilize by using PPP Layer2encapsulation?(Choose three.)A.VLAN supportpressionC.AuthenticationD.Sliding windowsE.Multilink supportF.Quality of serviceAnswer:B,C,E2Which two statements best describe the wireless security standard that is defined by WPA? (Choose two.)A.It specifies use of a static encryption key that must be changed frequently to enhance security.B.It requires use of an open authentication method.C.It specifies the use of dynamic encryption keys that change each time a client establishes a connection.D.It requires that all access points and wireless devices use the same encryption key.E.It includes authentication by PSK.Answer:C,E3While troubleshooting a connectivity problem,a network administrator notices that a port status LED on a Cisco Catalyst series switch is alternating green and amber.Which condition could this indicate?A.The port is experiencing errors.B.The port is administratively disabled.C.The port is blocked by spanning tree.D.The port has an active link with normal traffic activity.Answer:A4Refer to the exhibit.The network shown in the exhibit is running the RIPv2routing protocol.The network has converged, and the routers in this network are functioning properly.The FastEthernet0/0interface on R1goes down.In which two ways will the routers in this networkrespond to this change?(Choose two.)A.All routers will reference their topology database to determine if any backup routes to the192.168.1.0network are known.B.Routers R2and R3mark the route as inaccessible and will not accept any further routing updates from R1until their hold-down timers expire.C.Because of the split-horizon rule,router R2will be prevented from sending erroneous information to R1about connectivity to the192.168.1.0network.D.When router R2learns from R1that the link to the192.168.1.0network has been lost,R2will respond by sending a route back to R1with an infinite metric to the192.168.1.0network.E.R1will send LSAs to R2and R3informing them of this change,and then all routers will send periodic updates at an increased rate until the network again converges.Answer:C,D5Which three statements are correct about RIP version2?(Choose three.)A.It has the same maximum hop count as version1.B.It uses broadcasts for its routing updates.C.It is a classless routing protocol.D.It has a lower default administrative distance than RIP version1.E.It supports authentication.F.It does not send the subnet mask in updates.Answer:A,C,E6What should be part of a comprehensive network security plan?A.Allow users to develop their own approach to network security.B.Physically secure network equipment from potential access by unauthorized individuals.C.Encourage users to use personal information in their passwords to minimize the likelihood of passwords being forgotten.D.Delay deployment of software patches and updates until their effect on end-user equipment is well known and widely reported.E.Minimize network overhead by deactivating automatic antivirus client updates.Answer:B7How should a router that is being used in a Frame Relay network be configured to avoid split horizonissues from preventing routing updates?A.Configure a separate sub-interface for each PVC with a unique DLCI and subnet assigned to thesub-interface.B.Configure each Frame Relay circuit as a point-to-point line to support multicast and broadcast traffic.C.Configure many sub-interfaces on the same subnet.D.Configure a single sub-interface to establish multiple PVC connections to multiple remote router interfaces.Answer:A8Refer to the exhibit.Which statement describes DLCI17?A.DLCI17xn R2and R3.B.DLCI17describes a PVC on R2.It cannot be used on R3or R1.C.DLCI17is the Layer2address used by R2to describe a PVC to R3.D.DLCI17describes the dial-up circuit from R2and R3to the service provider. Answer:C9Which routing protocol by default uses bandwidth and delay as metrics?A.RIPB.BGPC.OSPFD.EIGRPAnswer:D10Refer to the exhibit.Switch-1needs to send data to a host with a MAC address of00b0.d056.efa4.What will Switch-1do with this data?A.Switch-1will drop the data because it does not have an entry for that MAC address.B.Switch-1will flood the data out all of its ports except the port from which the data originated.C.Switch-1will send an ARP request out all its ports except the port from which the data originated.D.Switch-1will forward the data to its default gateway.Answer:B11Refer to the exhibit.Why would the network administrator configure RA in this manner?A.To give students access to the InternetB.To prevent students from accessing the command prompt of RAC.To prevent administrators from accessing the console of RAD.To give administrators access to the InternetE.To prevent students from accessing the InternetF.To prevent students from accessing the Admin networkAnswer:B12While troubleshooting a network connectivity problem,a technician observes steady link lights on boththe workstation NIC and the switch port to which the workstation is connected.However,when the ping command is issued from the workstation,the output message"Request timed out."is displayed.At which layer of the OSI model does the problem most likely exist?A.The session layerB.The protocol layerC.The data link layerD.The access layerE.The network layerF.The application layerAnswer:E13A network administrator has configured two switches,named London and Madrid,to use VTP. However,the switches are not sharing VTP messages.Given the command output shown in the graphicWhy are these switches not sharing VTP messages?A.The VTP version is not correctly configured.B.The VTP operating mode is not correctly configured.C.The VTP domain name is not correctly configured.D.VTP pruning mode is disabled.E.VTP V2mode is disabled.F.VTP traps generation is disabled.Answer:C14On point-to-point networks,OSPF hello packets are addressed to which address?A.127.0.0.1B.172.16.0.1C.192.168.0.5D.223.0.0.1E.224.0.0.5F.254.255.255.255Answer:E15Refer to the exhibit.The switches on a campus network have been interconnected as shown.All of the switches are running Spanning Tree Protocol with its default settings.Unusual traffic patterns are observed and it is discovered that Switch9is the root bridge.Which change will ensure that Switch1will be selected as the root bridge instead of Switch9?A.Lower the bridge priority on Switch1.B.Raise the bridge priority on Switch1.C.Lower the bridge priority on Switch9.D.Raise the bridge priority on Switch9.E.Disable spanning tree on Switch9.F.Physically replace Switch9with Switch1in the topology.Answer:A16You just entered the following command:Company(config)#line console0A.Configure the terminal type.B.Enter protocol parameters for a serial line.C.Create a password on the console terminal line.D.Establish a terminal type4connection to a remote host.Answer:C17The part of Company network is shown below:According to the diagram,which of the following is true about the internetwork?pany2is the root bridge.B.Spanning Tree is not runn ing.C.No collisions can occur in traffic between CompanyB and CompanyC.panyD and Company Server1are in the same network.E.If Fa0/0is down on Company-R,PassGuideA cannot access Company Server1Answer:E18Which three of the following are reasons for assigning ports to VLANs on a switch?(Choose three.)A.to permit more devices to connect to the networkB.to iscC.to logically group hosts on the basis of functionD.to increase network securityAnswer:B,C,D19The Company network is shown below:Based on the information shown above,when the Company network administrator attempts to ping Host Company-PC2from Host Company-PC1and shown.What is a possible problem?A.The link between Company1and Company2is down.B.Interface Fa0/0on Company2is shutdown.C.The link between Company2and Company3is down.D.The default gateway on Company-PC1is incorrect.Answer:C20What is the objective of a default route?A.Offering routing to override the configured dynamic routing protocolB.Offering routing to a local web serverC.Offering routing from an ISP to a stub networkD.Offering routing to a destination that is not specified in the routing table and which is outside the local networkAnswer:D21Which three benefits are of VLANs?(Choose three.)A.To increase the size of collision domains.B.To allow logical grouping of users by function.C.To enhance network security.D.To increase the number of broadcast domains while decreasing the size of the broadcast domains. Answer:B,C,D22A default Frame Relay WAN is classified as what type of physical network?A.Point-to-pointB.Broadcast multi-accessC.Nonbroadcast multi-accessD.Nonbroadcast multipointE.Broadcast point-to-multipointAnswer:C23Refer to the exhibit.How many broadcast domains exist in the exhibited topology?A.OneB.TwoC.ThreeD.FourE.FiveF.SixAnswer:C24The command frame-relay map ip10.121.16.8102broadcast was entered on the router.Which of thefollowing statements is true concerning this command?A.This command should be executed from the global configuration mode.B.The IP address10.121.16.8is the local router port used to forward data.C.102is the remote DLCI that will receive the information.D.This command is required for all Frame Relay configurations.E.The broadcast option allows packets,such as RIP updates,to be forwarded across the PVC. Answer:E25Which type of attack is characterized by a flood of packets that are requesting a TCP connection to a server?A.Denial of serviceB.Brute forceC.ReconnaissanceD.Trojan horseAnswer:A26Which of the following are associated with the application layer of the OSI model?(Choose two.)A.PingB.TelnetC.FTPD.TCPE.IPAnswer:B,C27What are two recommended ways of protecting network device configuration files from outside network security threats?(Choose two.)A.Allow unrestricted access to the console or VTY ports.e a firewall to restrict access from the outside to the network devices.C.Always use Telnet to access the device command line because its data is automatically encrypted.e SSH or another encrypted and authenticated transport to access device configurations.E.Prevent the loss of passwords by disabling password encryption.Answer:B,D28Refer to the exhibit.Switch1has just been restarted and has passed the POST routine.Host A sends its initial frame to Host C.What is the first thing the switch will do as regards populating the switching table?A.Switch1will add192.168.23.4to the switching table.B.Switch1will add192.168.23.12to the switching table.C.Switch1will add000A.8A47.E612to the switching table.D.Switch1will add000B.DB95.2EE9to the switching table.Answer:C29Exhibit:The user of Host1wants to ping the DSL modem/router at192.168.1.254.Based on the Host1 ARP table that is shown in the exhibit,what will Host1do?A.Send a unicast ARP packet to the DSL modem/routerB.Send unicast ICMP packets to the DSL modem/routerC.Send Layer3broadcast packets to which the DSL modem/router respondsD.Send a Layer2broadcast that is received by Host2,the switch,and the DSL modem/router Answer:B30Which spread spectrum technology does the802.11b standard define for operation?A.IRB.DSSSC.FHSSD.DSSS and FHSSE.IR,FHSS,and DSSSAnswer:B31Refer to the exhibit.Assume that all router interfaces are operational and correctly configured.In addition,assume that OSPF has been correctly configured on router R2.How will the default route configured on R1affect the operation of R2?A.Any packet destined for a network that is not directly connected to router R1will be dropped.B.Any packet destined for a network that is not directly connected to router R2will be dropped immediately.C.Any packet destined for a network that is not directly connected to router R2will be dropped immediately because of the lack of a gateway on R1.D.The networks directly connected to router R2will not be able to communicate with the172.16.100.0, 172.16.100.128,and172.16.100.64subnetworks.E.Any packet destined for a network that is not referenced in the routing table of router R2will be directed to R1.R1will then send that packet back to R2and a routing loop will occur.Answer:E32A network interface port has collision detection and carrier sensing enabled on a shared twisted pair network.From this statement,what is known about the network interface port?A.This is a10Mb/s switch port.B.This is a100Mb/s switch port.C.This is an Ethernet port operating at half duplex.D.This is an Ethernet port operating at full duplex.E.This is a port on a network interface card in a PC.Answer:C33Refer to the topology and router configuration shown in the graphic.A host on the LAN is accessing an FTP server across the Internet.Which of the following addresses could appear as a source address for the packets forwarded by the router to the destination server?A.10.10.0.1B.10.10.0.2C.199.99.9.33D.199.99.9.57E.200.2.2.17F.200.2.2.18Answer:D34What is the purpose of the Cisco VLAN Trunking Protocol?A.To allow traffic to be carried from multiple VLANs over a single link between switchesB.To allow native VLAN information to be carried over a trunk linkC.To allow for managing the additions,deletions,and changes of VLANs between switchesD.To provide a mechanism to manually assign VLAN membership to switch portsE.To provide a mechanism to dynamically assign VLAN membership to switch portsAnswer:C35Which two statements describe the Cisco implementation of VLANs?(Choose two.)A.VLAN1is the default Ethernet VLAN.B.CDP advertisements are only sent on VLAN1002.C.By default,the switch IP address is in VLAN1005.D.VLANs1002through1005are automatically created and cannot be deleted.Answer:A,D36Refer to the exhibit.What two results would occur if the hub were to be replaced with a switch that is configured with one Ethernet VLAN?(Choose two.)A.The number of collision domains would remain the same.B.The number of collision domains would decrease.C.The number of collision domains would increase.D.The number of broadcast domains would remain the same.E.The number of broadcast domains would decrease.F.The number of broadcast domains would increase.Answer:C,D37Three access points have been installed and configured to cover a small office.What term defines thewireless topology?A.BSSB.IBSSC.ESSD.SSIDAnswer:C38A TCP/IP transfer is diagrammed in the exhibit.A window size of three has been negotiated for this transfer.Which message will be returned from the receiver to the sender as part of this TCP/IP transfer?A.Send ACK1-3B.Send ACK3C.Send ACK4D.Send ACK4-6E.Send ACK6F.Send ACK7Answer:C39Which two statements are true based the output of the show frame-relay lmi command issued on the Branch router?(Choose two.)A.LMI messages are being sent on DLCI0.B.LMI messages are being sent on DLCI1023.C.Interface Serial0/0is not configured to encapsulate Frame Relay.D.The Frame Relay switch is not responding to LMI requests from the router.E.The LMI exchange between the router and Frame Relay switch is functioning properly.F.The router is providing a clock signal on Serial0/0on the circuit to the Frame Relay switch. Answer:A,D40.Refer to the graphic.A static route to the10.5.6.0/24network is to be configured on the HFD router. Which commands will accomplish this?(Choose two.)A.HFD(config)#ip route10.5.6.00.0.0.255fa0/0B.HFD(config)#ip route10.5.6.00.0.0.25510.5.4.6C.HFD(config)#ip route10.5.6.0255.255.255.0fa0/0D.HFD(config)#ip route10.5.6.0255.255.255.010.5.4.6E.HFD(config)#ip route10.5.4.60.0.0.25510.5.6.0F.HFD(config)#ip route10.5.4.6255.255.255.010.5.6.0Answer:CD41.What should be done prior to backing up an IOS image to a TFTP server?(Choose three.)A.Make sure that the server can be reached across the network.B.Check that authentication for TFTP access to the server is set.C.Assure that the network server has adequate space for the IOS image.D.Verify file naming and path requirements.E.Make sure that the server can store binary files.F.Adjust the TCP window size to speed up the transfer.Answer:ACD42.What are the possible trunking modes for a switch port?(Choose three.)A.transparentB.autoC.onD.desirableE.clientF.forwardingAnswer:BCD43.The network172.25.0.0has been divided into eight equal subnets.Which of the following IP addresses can be assigned to hosts in the third subnet if the ip subnet-zero command is configured on the router?(Choose three.)A.172.25.78.243B.172.25.98.16C.172.25.72.0D.172.25.94.255E.172.25.96.17F.172.25.100.16Answer:ACD44.Refer to the graphic.Host1cannot receive packets from Host2.Assuming that RIP v1is the routing protocol in use,what is wrong with the IP configuration information shown?(Choose two.)A.The fa0/1interface of router R2has been assigned a broadcast address.B.The fa0/1network on router R2overlaps with the LAN attached to R1.C.Host2has been assigned the incorrect subnet mask.D.Host1has been configured with the255.255.248.0subnet mask.E.Host2on router R2is on a different subnet than its gateway.Answer:BC45.What are three valid reasons to assign ports to VLANs on a switch?(Choose three.)A.to make VTP easier to implementB.to isolate broadcast trafficC.to increase the size of the collision domainD.to allow more devices to connect to the networkE.to logically group hosts according to functionF.to increase network securityAnswer:BEF46.Refer to the topology shown in the exhibit.Which ports will be STP designated ports if all the links areoperating at the same bandwidth?(Choose three.)A.Switch A-Fa0/0B.Switch A-Fa0/1C.Switch B-Fa0/0D.Switch B-Fa0/1E.Switch C-Fa0/0F.Switch C-Fa0/1Answer:BCD47.Which statements describe two of the benefits of VLAN Trunking Protocol?(Choosetwo.)A.VTP allows routing between VLANs.B.VTP allows a single switch port to carry information to more than one VLAN.C.VTP allows physically redundant links while preventing switching loops.D.VTP simplifies switch administration by allowing switches to automatically share VLAN configuration information.E.VTP helps to limit configuration errors by keeping VLAN naming consistent across the VTP domain.F.VTP enhances security by preventing unauthorized hosts from connecting to the VTP domain. Answer:DE48What are two results of entering the Switch(config)#vtp mode client command on a Catalyst switch?(Choose two.)A.The switch will ignore VTP summary advertisements.B.The switch will forward VTP summary advertisements.C.The switch will process VTP summary advertisementsD.The switch will originate VTP summary advertisements.E.The switch will create,modify and delete VLANs for the entire VTP domain.Answer:BC49.A network administrator issues the ping192.168.2.5command and successfully tests connectivity to a host that has been newly connected to the network.Which protocols were used during the test? (Choose two.)A.ARPB.CDPC.DHCPD.DNSE.ICMPAnswer:AE50.Refer to the exhibit.Host A is to send data to Host B.How will Router1handle the data frame received from Host A?(Choose three.)A.Router1will strip off the source MAC address and replace it with the MAC address on the forwardingFastEthernet interface.B.Router1will strip off the source IP address and replace it with the IP address on the forwarding FastEthernetinterface.C.Router1will strip off the destination MAC address and replace it with the MAC address of Host B.D.Router1will strip off the destination IP address and replace it with the IP address of Host B.E.Router1will forward the data frame out interface FastEthernet0/1.F.Router1will forward the data frame out interface FastEthernet0/2.Answer:ACF51.Refer to the exhibit.What will Router1do when it receives the data frame shown?(Choose three.)A.Router1will strip off the source MAC address and replace it with the MAC address0000.0c36.6965.B.Router1will strip off the source IP address and replace it with the IP address192.168.40.1.C.Router1will strip off the destination MAC address and replace it with the MAC address0000.0c07.4320.D.Router1will strip off the destination IP address and replace it with the IP address of192.168.40.1.E.Router1will forward the data packet out interface FastEthernet0/1.F.Router1will forward the data packet out interface FastEthernet0/2.Answer:ACF52.Refer to the exhibit.Host A pings Host B.What source MAC address and source IP address are contained in the frame as the frame leaves R2destined for host B?A.abcd.abcd.a001B.abcd.abcd.b002C.abcd.abcd.c003D.10.2.0.15E.10.0.64.1F.10.0.128.15Answer:BD53.Refer to the exhibit.A network associate has configured OSPF with the command:City(config-router)#network192.168.12.640.0.0.63area0After completing the configuration,the associate discovers that not all the interfaces are participating in OSPF.Which three of the interfaces shown in the exhibit will participate in OSPF according to this configuration statement?(Choose three.)A.FastEthernet0/0B.FastEthernet0/1C.Serial0/0D.Serial0/1.102E.Serial0/1.103F.Serial0/1.104Answer:BCD54.A Catalyst2950needs to be reconfigured.What steps will ensure that the old configuration is erased?(Choose three.)A.Erase flash.B.Restart the switch.C.Delete the VLAN database.D.Erase the runnin configuration.E.Erase the startup configuration.F.Modify the configurationregister.Answer:BCE55.Refer to the exhibit.The FMJ manufacturing company is concerned about unauthorized access to the Payroll Server.The Accounting1,CEO,Mgr1,and Mgr2workstations should be the only computers with access to the Payroll Server.What two technologies should be implemented to help prevent unauthorized access to the server?(Choose two.)A.access listsB.encrypted router passwordsC.STPD.VLANsE.VTPF.wireless LANsAnswer:AD56.Refer to the exhibit.What commands must be configured on the2950switch and the router to allow communication between host1and host2?(Choose two.)A.Router(config)#interface fastethernet0/0Router(config-if)#ip address192.168.1.1255.255.255.0Router(config-if)#no shut downB.Router(config)#interface fastethernet0/0Router(config-if)#no shut downRouter(config)#interface fastethernet0/0.1Router(config-subif)#encapsulation dot1q10Router(config-subif)#ip address192.168.10.1255.255.255.0Router(config)#interface fastethernet0/0.2Router(config-subif)#encapsulation dot1q20Router(config-subif)#ip address192.168.20.1255.255.255.0C.Router(config)#router eigrp100Router(config-router)#network192.168.10.0Router(config-router)#network192.168.20.0D.Switch1(config)#vlan databaseSwitch1(config-vlan)#vtp domain XYZSwitch1(config-vlan)#vtp serverE.Switch1(config)#interface fastethernet0/1Switch1(config-if)#switchport mode trunkF.Switch1(config)#interface vlan1Switch1(config-if)#ip default-gateway192.168.1.1Answer:BE57.Which three Layer2encapsulation types would be used on a WAN rather than a LAN?(Choose three.)A.HDLCB.EthernetC.Token RingD.PPPE.FDDIF.Frame RelayAnswer:ADF58.Refer to the exhibit.The two connected ports on the switch are not turning orange or green.What would be the most effective steps to troubleshoot this physical layer problem?(Choose three.)A.Ensure that the Ethernet encapsulations match on the interconnected router and switch ports.B.Ensure that cables A and B are straight-through cables.C.Ensure cable A plugged into a trunk port.D.Ensure the switch has power.E.Reboot all of the devices.F.Reseat all cables.Answer:BDF59.What can be determined from the line of show ip route output shown in the exhibit?(Choose two.)A.The next routing update can be expected in35seconds.B.The IP address10.10.10.6is configured on S0/1.C.The IP address10.10.10.8is configured on S0/1.D.This route is using the default administrative distance.E.The10.10.10.8network is two hops away from this router.Answer:DE60.Refer to the exhibit.All of the routers in the network are configured with the ip subnet-zero command.Which network addresses should be used for Link A and Network A?(Choose two.)work A-172.16.3.48/26work A-172.16.3.128/25work A-172.16.3.192/26D.Link A-172.16.3.0/30E.Link A-172.16.3.40/30F.Link A-172.16.3.112/30Answer:BD61.Which two subnetworks would be included in the summarized address of172.31.80.0/20? (Choose two.)A.172.31.17.4/30B.172.31.51.16/30C.172.31.64.0/18D.172.31.80.0/22E.172.31.92.0/22F.172.31.192.0/18Answer:DE62.The network administrator has discovered that the power supply has failed on a switch in the company LAN and that the switch has stopped functioning.It has been replaced with a Cisco Catalyst 2950series switch.What must be done to ensure that this new switch becomes the root bridge on the network?A.Lower the bridge prioritynumber.B.Change the MAC address of the switch.C.Increase the VTP revision number for the domain.D.Lower the root path cost on the switch ports.E.Assign the switch an IP address with the lowestvalue.Answer:A63.Refer to the exhibit.Assume that all of the router interfaces are operational and configured correctly.How will router R2be affected by the configuration of R1that is shown in the exhibit?A.Router R2will not form a neighbor relationship with R1.B.Router R2will obtain a full routing table,including a default route,from R1.C.R2will obtain OSPF updates from R1,but will not obtain a default route from R1.D.R2will not have a route for the directly connected serial network,but all other directly connected networks will be present,as well as the two Ethernet networks connected to R1.Answer:D64.Which three IP addresses can be assigned to hosts if the subnet mask is/27and subnet zero is usable? (Choose three.)A.10.15.32.17B.17.15.66.128C.66.55.128.1D.135.1.64.34E.129.33.192.192F.192.168.5.63Answer:ACD65.Refer to the exhibit.A packet with a source IP address of192.168.2.4and a destination IP address of 10.1.1.4arrives at the HokesB router.What action does the router take?A.forwards the received packet out the Serial0/0interfaceB.forwards a packet containing an EIGRP advertisement out the Serial0/1interfaceC.forwards a packet containing an ICMP message out the FastEthernet0/0interfaceD.forwards a packet containing an ARP request out the FastEthernet0/1interfaceAnswer:C66.Refer to the exhibit.From RouterA,a network administrator is able to ping the serial interface of RouterB but unable to ping any of the subnets attached to RouterB.Based on the partial outputs in the exhibit,what could be the problem?。

ccna考试题库最新版CCNA（Cisco Certified Network Associate）认证是全球范围内最受欢迎的网络工程师认证之一，具备CCNA认证可以证明一个人在建立、规划、运行、安装和配置中等规模的局域网和广域网方面的专业知识。

为了帮助广大考生顺利通过CCNA考试，不断更新的CCNA考试题库至关重要。

以下是最新版本的CCNA考试题库，希望对考生们有所帮助。

第一部分：网络基础知识1. 什么是OSI七层模型？简要介绍每一层的功能。

2. TCP和UDP之间有哪些区别？请分别举例说明。

3. 什么是IP地址？IP地址的类型有哪些？请列举并简要介绍各自的特点。

4. 什么是子网掩码？为什么在网络中使用子网掩码？5. 简述常见的网络设备有哪些，以及各自的功能与作用。

第二部分：路由和交换技术1. 路由器和交换机之间有何区别？请进行比较并指出各自的优势和劣势。

2. 什么是VLAN？VLAN的作用及在网络中的应用场景是什么？3. OSPF和EIGRP是两种常见的路由协议，请比较它们的特点并举例说明。

4. 请解释静态路由和动态路由的概念以及在网络中的应用。

5. 交换机在网络中扮演什么角色？交换机的MAC地址表是如何工作的？第三部分：网络安全和管理1. 网络安全的重要性是什么？请列举几种常见的网络安全威胁并介绍应对策略。

2. 什么是ACL（访问控制列表）？ACL的作用是什么？请给出一个ACL的配置示例。

3. VPN是什么？VPN的工作原理及在企业网络中的应用。

4. SNMP是网络管理中常用的协议，它的作用是什么？请解释SNMP中的几个重要概念。

5. 如何保护无线网络的安全？请列举几种方法。

第四部分：WAN技术1. 什么是WAN？WAN的主要特点是什么？2. PPP协议和HDLC协议分别是什么？请比较它们的异同。

3. 什么是Frame Relay？Frame Relay的工作原理及在WAN中的应用。

4. 请解释T1和E1的概念，以及它们在传输速率和应用方面的差异。

C C N A考试题(总9页) -CAL-FENGHAI.-(YICAI)-Company One1-CAL-本页仅作为文档封面，使用请直接删除第一部分：选择题1：提供可靠数据传输、流控的是OSI的第几层（）A、表示层B、网络层C、传输层D、会话层E、链路层2：子网掩码产生在那一层（）A、表示层B、网络层C、传输层D、会话层3：当路由器接收的IP报文的目的地址不是本路由器的接口IP地址，并且在路由表中未找到匹配的路由项，采取的策略是（）A、丢掉该分组B、将该分组分片C、转发该分组D、以上答案均不对4：当一台主机从一个网络移到另一个网络时，以下说法正确的是（）A、必须改变它的IP地址和MAC地址B、必须改变它的IP地址，但不需改动MAC地址C、必须改变它的MAC地址，但不需改动IP地址D、MAC地址、IP地址都不需改动5：ISO提出OSI的关键是（）A、系统互联B、提高网络速度C、为计算机制定标准D、经济利益6：OSI参考模型按顺序有哪些层（）A、应用层、传输层、网络层、物理层B、应用层、表示层、会话层、网络层、传输层、数据链路层、物理层C、应用层、表示层、会话层、传输层、网络层、数据链路层、物理层D、应用层、会话层、传输层、物理层7：LAN的拓扑形式一般以（）为主。

A、总线型B、环型C、令牌环D、载波侦听与冲突检测CSMA/CD8：网段地址154.27.0.0的网络，若不做子网划分，能支持（）台主机A、254B、1024C、65,534D、16,777,2069：路由器网络层的基本功能是（）。

A、配置IP地址B、寻找路由和转发报文C、将MAC地址解释成IP地址10：选出基于TCP协议的应用程序（）。

A、PINGB、TFTPC、TELNETD、OSPF11：某公司申请到一个C类IP地址，但要连接6个的子公司，最大的一个子公司有26台计算机，每个子公司在一个网段中，则子网掩码应设为（）。

A、255.255.255.0B、255.255.255.128C、255.255.255.192D、255.255.255.22412：B类地址的缺省掩码是（）。

ccna考试试题库CCNA（Cisco Certified Network Associate）考试是思科认证网络专家的初级认证，主要测试考生在网络基础、路由、交换、无线和安全等方面的知识。

以下是一些模拟CCNA考试的试题和答案：1. 什么是子网掩码，它有什么作用？答案：子网掩码是一种IP地址的附加信息，用于指定IP地址中网络部分和主机部分的界限。

它的作用是允许路由器区分IP地址中的网络地址和主机地址，从而实现不同网络之间的路由。

2. 描述静态路由和动态路由的区别。

答案：- 静态路由：由网络管理员手动配置的路由信息，不随网络结构的变化而自动调整。

- 动态路由：由路由器根据网络拓扑的变化自动生成和更新的路由信息。

3. 什么是VLAN，它有什么好处？答案： VLAN（虚拟局域网）是一种在交换机上划分不同网络的技术，即使物理上连接在同一交换机上，也可以属于不同的VLAN。

VLAN的好处包括提高安全性、减少广播域、提高网络管理的灵活性等。

4. 简述TCP和UDP的区别。

答案：- TCP（传输控制协议）：提供可靠的、面向连接的传输服务，有流量控制和拥塞控制机制。

- UDP（用户数据报协议）：提供不可靠的、无连接的传输服务，适用于对实时性要求高的应用。

5. 什么是DHCP，它的作用是什么？答案： DHCP（动态主机配置协议）是一种网络管理协议，用于自动分配IP地址和其他网络配置信息给网络中的设备。

它的作用是简化网络配置，避免IP地址冲突。

6. 什么是NAT，它在网络中扮演什么角色？答案： NAT（网络地址转换）是一种技术，允许多个设备共享一个公共IP地址与互联网通信。

它在网络中扮演的角色是节省IP地址资源，隐藏内部网络结构。

7. 什么是STP（生成树协议）？答案： STP（生成树协议）是一种网络协议，用于在局域网中防止网络环路的产生。

通过创建一个无环的逻辑拓扑，STP确保网络的稳定性和可靠性。

8. 描述OSPF（开放最短路径优先）协议的工作原理。