CCNA练习题答案.doc

测试一问题 1 给定二进制值11000001。它等于十进制的193。 正确答案： 对 问题 2 如果路由器有一个需要其路由的分组，但是路由器在其路由选择表中不能找到目的网络号，路由器将会丢弃此分组。 正确答案： 对 问题 3 下面哪些中继方式是Cisco专有的？ 正确答案： B.802.1 D. ISL 问题 4 哪个拓扑描述的是设备之间如何通信的? 正确答案： B. 逻辑 问题 5 哪个是一种为一个公司到其他业务伙伴之间提供安全连接的网络。 正确答案： C. Extranet(外部网络) 问题 6 下面哪个可感知OSI参考模型的47层，以便对如何为用户获得信息做出智能的决策? 正确答案： A. CN 问题 7 哪个同时具有物理和逻辑环型拓扑?正确答案： B. FDDI 问题 8 CSMA/CD代表下面哪个? 正确答案： B. Carrier Sense Multiple Access/Collision Detect 问题 9 哪个使用类型字段? 正确答案： A. EthernetII 问题 10 Which of the following statements are true regarding a network using a subnet mask of ? (Choose three) 正确答案： A. It corresponds to a Class A address with 13 bits borrowed C. The network address of the last subnet will have 248 in the 3rd octet. D. The subnetwork numbers will be in multiples of 8 问题 11 Which of the following IP hosts would be valid for PC users, assuming that a /28 network mask was used for all of the networks? (Choose all that apply.) 正确答案： A. 3 B. 6 C. 7 问题 12 进入配置模式，输入命令:conf t 正确答案： 对 问题 13 哪层提供硬件寻址? 正确答案： C. 数据链路 问题 14 下面哪个同时具有物理星型拓扑和逻辑环型拓扑? 正确答案： C. 令牌环 问题 15 从闪存中备份IOS镜像时，copy flash tftp命令将提示用户输入以下哪些信息？ 正确答案： A. TFTP server IP address C. Source filename D. Destination filename 问题 16 于连接一个很小地域内的连网设备，例如大厦的一层、一座大厦或一个园区? 正确答案： B. LAN 问题 IEEE数据链路层的哪个组件指定网络协议？ 正确答案： A. LLC 问题 18 下面哪个描述可从任何位置连网的用户。 正确答案： C. 移动用户 问题 19 在子接口配置模式中想要彻底地回到特权EXEC模式。应该键入什么？(选所有的可能) 正确答案： A. CTRL-Z B. end 问题 20 下面的以太网哪个同时具有物理和逻辑总线拓扑? 正确答案： B. 10Base2和10Base5 问题 21图中的家庭网络可能用到了哪些设备? 正确答案： A. 100Mbps以太网适配器 B. Category 5 双铰线电缆 C. 以太网集线器 问题 22 利用enable命令可以从用户EXEC模式进入特权EXEC 模式。 正确答案： 对 问题 23 下列哪项存储在ROM中？ 正确答案： A. POST B. ROMMON 问题 24子网掩码的功能是区分网络地址、主机地址和定向广播地址。 正确答案： 对 问题 25 下面哪个提供高速的基础设施，以便在存储设备和文件服务器间传送数据? 正确答案： A. SAN 问题 26 要在路由器上启用IP路由选择，必须做什么？ 正确答案： A. 启用路由选择协议 C. 向路由器接口分配IP地址 问题 27 将下列各层从高到低排列为正确的顺序：会话层（a），表示层（b），物理层（c），数据链路层（d），网络层（e），应用层（f），传输层（g）。 正确答案： f,b,a,g,e,d,c 问题 28 哪条路由器命令执行覆盖的过程？ 正确答案： copy running-config start copy running-config tftp 问题 29 下面哪个是SAN的缺点? 正确答案： A. 成本 问题 30 会话层使用下列哪种标准或协议? 正确答案： B. NFS 问题 31哪个拓扑在所有设备之间使用单一线路来连接?正确答案： A. 总线 问题 32 下面哪个使用吉比特以太网介质类型? 正确答案： D. LAN和MAN 问题 33 下面哪个使用吉比特以太网介质类型? 正确答案： D. LAN和MAN 问题 34 如果想查看show 命令的参数清单，则用户会键入show ? 正确答案： 对 问题 35默认哪些度量值组件在IGRP中使用？ 正确答案： A. 延迟 D. 带宽 测试二问题 1 Which of the following IP hosts would be valid for PC users, assuming that a /28 network mask was used for all of the networks? (Choose all that apply.) 正确答案： A. 3 B. 6 C. 7 问题 2 哪个拓扑描述的是设备之间如何通信的? 正确答案： B. 逻辑 问题 3 要让路由器从ROM中的迷你IOS启动，可以输入路由器配置命令：boot system rom或者config-register 0x2401 正确答案： 对 问题 4 下面哪个可感知OSI参考模型的47层，以便对如何为用户获得信息做出智能的决策? 正确答案： A. CN 问题 5 路由器自动地保存其配置。 正确答案： 错 问题 6 哪个是一种为一个公司到其他业务伙伴之间提供安全连接的网络。 正确答案： C. Extranet(外部网络) 问题 7 Which of the following IP addresses fall into the CIDR block of /22? (Select three) 正确答案： A. 4 B. 55 C. 28 问题 8 用于连接一个很小地域内的连网设备，例如大厦的一层、一座大厦或一个园区? 正确答案： B. LAN 问题 9 下面哪个使用吉比特以太网介质类型? 正确答案： D. LAN和MAN 问题 10 要为1900系列交换机指定名称switch1，输入命令: hostname switch 正确答案： 错 问题 11 下面哪个是SAN的缺点? 正确答案： A. 成本 问题 12 You have the following :/27. Which of the following addresses can be allocated to hosts on the resulting subnet? 正确答案： A. C. 3 D. 1 问题 13 Your ISP assigned you a full class A address space. From this, you need at least 300 sub-networks that can support at least 50 hosts each. Which of the subnet masks below are capable of satisfying your needs? (Select two). 正确答案： A. B. 问题 14 哪个用于提供可靠的连接。 正确答案： B. 序号和确认 问题 15 要将配置寄存器的值改为0x2142，可以输入路由器配置模式命令：config-register 0x2402 正确答案： 对 问题 16 下面哪个提供高速的基础设施，以便在存储设备和文件服务器间传送数据? 正确答案： A. SAN 问题 17 下面哪个同时具有物理星型拓扑和逻辑环型拓扑? 正确答案： C. 令牌环 问题 18 要删除在NVRAM中的用户的配置文件，可以使用路由器命令： erase start-config 正确答案： 对 问题 19 Which of the following IP addresses for the network 2/28 can be assigned to hosts? (Choose three) 正确答案： B. 4 C. 5 D. 3 问题 20 哪个同时具有物理和逻辑环型拓扑?正确答案： B. FDDI 问题 21 Using a subnet mask of 40, which of the IP addresses below can you assign to the hosts on this subnet? (Select all that apply) 正确答案： A. 3 B. 6 C. 7 问题 22 哪个拓扑在所有设备之间使用单一线路来连接?正确答案： A. 总线 问题 23 会话层使用下列哪种标准或协议? 正确答案： B. NFS 问题 24 哪个使用类型字段? 正确答案： A. EthernetII 问题 25 将下列各层从高到低排列为正确的顺序：会话层（a），表示层（b），物理层（c），数据链路层（d），网络层（e），应用层（f），传输层（g）。 正确答案： f,b,a,g,e,d,c 问题 26 哪层提供硬件寻址? 正确答案： C. 数据链路 问题 27 要删除在NVRAM中的用户的配置文件，可以使用路由器命令： erase start-config 正确答案： 对 问题 28 下面哪个描述可从任何位置连网的用户。 正确答案： C. 移动用户 问题 29 网络层解决以下所有的问题除了哪个？ 正确答案： C. 通过使用物理地址分层 问题 30 CSMA/CD代表下面哪个? 正确答案： B. Carrier Sense Multiple Ac 问题 31 下面的以太网哪个同时具有物理和逻辑总线拓扑? 正确答案： B. 10Base2和10Base5 问题 32 You have a class B network with a mask. Which of the statements below are true of this network? (Select all valid answers) 正确答案： A. 254 usable subnet. B. 254 usable hosts persubnet 问题 33 Which two of the addresses below are available for host addresses on the subnet 9/28? (Select two answer choices) 正确答案： A. 7 B. 9 问题 34 IEEE数据链路层的哪个组件指定网络协议？ 正确答案： A. LLC 测试三问题1 16 networks and 14 hosts are available per subnet if you apply a /28 mask to the class C network. 正确答案： 对 问题 2 You are the network administrator at TestKing. TestKing has been provided with the network address /24. The TestKing CEO wants to know how many subnetworks this address provides, and how many hosts can be supported on each subnet. What would your reply be? (Choose all that apply) 正确答案： A. One network with 254 hosts. 问题 3 55./18 is an example of a valid unicast host IP address. 正确答案： 对 问题 4 Based on this diagram, which two devices can be used to complete the connection between the WAN router at the customer site and the service provider? (Choose two.) 正确答案： A. CSU/DSU B. modem 反馈： DTE is an abbreviation for Data Terminal Equipment, and refers to an end instrument that converts user information into signals for transmission, or reconverts the received signals into user information. A DTE device communicates with the DCE, such as a modem. 问题 5 A company has the following addressing scheme requirements: -uses a Class B IP address -currently has 60 subnets -has a maximum of 1000 computers on any network segment -needs to leave the fewest unused addresses in each subnet -uses RIP v1 Which subnet mask is appropriate to use in this network? 正确答案： A. 问题 6 TestKing has four offices, each with its own network, as shown in the graphic. Three of the networks have approximately 50 hosts each, and one network has 10 hosts. The multi-vendor routers are connected by serial links that use separate subnetwork numbers.The TestKing network has leased one Class C address to be used for allnetworks and serial links, and they do not wish to replace any of their existingrouters.Which routing protocol would be most appropriate for this scenario? 正确答案： A. RIP version 2 反馈： The question describes 2 important requirements. The first is the fact that a routing protocol that supports VLSM is needed, as specified by the fact that one class C address range is to be used for all networks. The second is that routers from multiple vendors are being used, so the routing protocol chosen must be non-proprietary. RIP version 2 is a standards based routing protocol that supports variable length subnet masking (VLSM). Note that OSPF would also be a viable choice, but it was not one of the answer choices. 问题 7 The TestKing network was assigned the Class C network from the ISP. If the administrator at TestKing were to subnet this class C network using the 24 subnet mask, 30 hosts they will be able to support on each subnet. 正确答案： 对 问题 8 Which routing protocols can be used within the enterprise network shown in the diagram? (Choose three.) 正确答案： A. RIP v2 B. OSPF C. EIGRP 反馈： In this network there are IP subnets which use variable length subnet masks. RIP V2, OSPF and EIGRP are the interior routing protocols that support VLSM. 问题 9 You need to implement the use of a routing protocol that meets the following requirements: 1. Converges quickly 2. Supports VLSM, CIDR, IP, and IPX. 3. Uses minimal bandwidth for routing updates. Which one of the following routing protocols would be the best choice? 正确答案： A. EIGRP 问题 10 Topologies have two types. 正确答案： 对 反馈： phisical and logic Topologies. 问题 11 If an Ethernet port on router was assigned an IP address of /20, what is the maximum number of hosts allowed on this subnet? 正确答案： C. 4094 问题 12 A new subnet with 12 hosts in the TestKing network has been added. Which subnet address should this network use to provide enough useable addresses while wasting the fewest addresses? 正确答案： B. 6/28 问题 13 A new subnet with 60 hosts has been added to the TestKing network shown below. Which subnet address should this network use to provide enough usable addresses while wasting the fewest addresses? Exhibit: 正确答案： B. 4/26 反馈： A subnet mask of 92 (/26) will be needed to support 60 hosts. Option B will allow for this number of hosts, and the next available IP subnet in the subnet that is not al-ready used in the network is 4. 问题 14 A brand new network application is required for the Acme Company, and they are consid-ering the use of a connectionless service. What are the characteristics of a connectionless service? (Select two answer choices) 正确答案： B. It uses a Non-reliable transport mechanism C. It is less bandwidth-intensive than connection oriented services 问题 15 You work as network consultant. Your customer, TestKing Inc, has a class C network license. TestKing wants you to subnet the network to provide a separate subnet for each of its 5 de-partments. Each subnet must support at least 24 hosts. Which network mask will be use? 正确答案： B. 24 反馈： The default subnet mask for class C network is . If one has to create 5 subnets, then 3 bits are required. With 3 bits we can create 6 subnets. Remaining 5 bits are used for Hosts. One can create 30 hosts using 5 bits in host field. 问题 16 Consider the /24 network in this exhibit. This network uses RIP v2. Which combi-nation of subnetwork assignments will satisfy the requirements for networks A, B, and C of this design? (Select three) 正确答案： A. Network A = 28/25 B. Network B = /30 C. Network C = 4/26 反馈： To properly answer this question, it is best to start from the end, which is network C. Since net-work C requires at least 55 host addresses, a /26 network must be used. A network mask of /26 will provide for 62 usable IP addresses while a /27 network will . 问题 17 In the TestKing network shown below, which subnet address could a network administrator use for Network A on the left? Exhibit: 正确答案： C. 28/26 问题 18 In network that support VLSM, which network mask should be used for point-to-point WAN links in order to reduce waste of IP addresses? 正确答案： B. /30 反馈： A 30-bit mask is used to create subnets with two valid host addresses. This is the exact number needed for a point-to-point connection. 问题 19 Using a Class C IP network, which subnet mask will provide one usable subnet per depart-ment while allowing enough usable host addresses for each department specified in the graphic? 正确答案： C. 24 反馈： Choice C will provide for 8 separate subnets with 30 usable hosts per subnet. Since we only re-quire 5 different subnets with at most 16 users, this will suffice. 问题 20 In this diagram, OSPF is used as the routing protocol between the corporate office and the offices on the left side of the diagram. An ISDN link provides connectivity from the central corporate router to the remote sales office on the right side of the diagram.Which type of route should the corporate office use to reach the router on the right side of the diagram if the overhead on the ISDN link is to be kept to a minimum? 正确答案： C. A static route 反馈： A static route uses the least amount of overhead because no routing protocol informationwill be exchanged over the ISDN link. As long as the ISDN link is up, the static route willalways remain in the routing table of the corporate router. 问题 21 You are the network administrator at TestKing. TestKing has been assigned the class C IP address by its Internet Service Provider. If you divide the network range by using the 24 subnet mask, how many hosts can be supported on each ? 正确答案： C. 30 反馈： The subnet mask 24 is a 27 bit mask 11111111.11111111.11111111.11100000). It uses 3 bits from the host Id for the network ID, leaving 5 bits for host addresses. We can calculate the number of hosts supported by this subnet by using the 2n-2 formul.问题 22 You have a Class C network, and you need ten subnets. You wish to have as many addresses available for hosts as possible. Subnet masks 40 you should use. 正确答案： 对 问题 23 Which of the following statements are true regarding how router A will chose a path to router E? (Choose three) 正确答案： A. If RIP and IGRP are both configured on router A, the router will use the route learned by RIP. B. If RIP is the routing protocol, router A will determine all paths have an equal cost. C. If IGRP is the routing protocol, router A will determine that path ADE has the lowest cost. 反馈： RIP simply uses hop counts as the metric for path determination, so RIP will see all routes as equal in this case. IGRP uses bandwidth and delay, by default, so it will prefer the paths over the T3 links. By default, IGRP routes are always preferred over RIP. 问题 24 How would you express the binary number: 10101010 in its decimal and hexadecimal forms? 正确答案： B. Decimal=170, hexadecimal=AA 反馈： For the binary equivalent of 10101010 to Decimal, the answer is 128+32+8+2=170. For the hexa-decimal number, we need to break up the binary number into two bytes of 1010 and 1010. Each one in binary is then 10 and 10, which is A and A in hexadecimal. 问题 25 You are a network administrator and you need to implement a routing protocol on your network that provides: * Scalability * VLSM support * Minimal overhead * Support for connecting networks using routers of multiple vendors Which of the following routing protocol would best serve your needs? 正确答案： D. OSPF 反馈： Since one of the requirements is that the routing protocol must support other vendors, our only choices are RIP and OSPF. Since RIP version 1 does not support VLSM, OSPF is the only choice. 问题 26 A network associate needs to configure a router by connecting a remote computer to the router through the router auxiliary port. Which two statements describe the hardware re-quired to make the connection to the router? (Choose two.) 正确答案： A. The auxiliary port must be connected to a modem. D. The technician needs an RJ-45 to DB25 adapter. 反馈： When a modem is connected to the auxiliary port, a remote user can dial in to the router and con-figure it. Use the light blue console cable and the DB-9-to-DB-25 connector adapter that came in the router accessory kit. Connect the RJ-45 end of the adapt 问题 27 The network with the IP address /19 is to be configured on the TestKing router with the partial configuration shown in the graphic. Which of the following statements describes the number of available subnets and hosts that will result from this 正确答案： D. There are 8 usable subnets, with 8190 usable host addresses. 反馈： The /19 will have 3 bits in the network portion, and 13 bits in the host portion. This will allow for 23 = 8 networks and 213 = 8192 hosts available for each network (8190 usable). Since the IP subnet-zero command is used the first network is a 问题 28 The TestKing network consists of a small office with twenty-five employees that has one connection to the Internet through the TK1 router. What routing configurations are recom-mended on the TK1 and ISP routers? 正确答案： D. A default route on TK1 and a static route on the ISP router. 问题 29 You are a technician at TestKing. Your newly appointed TestKing trainee wants to know what the CDP is. What would your reply be? (Choose all that apply.) 正确答案： A. It is globally enabled by default on Cisco routers. C. It is a proprietary protocol. D. It can be used to gather hardware and protocol information about neighbor devices. 反馈： Cisco Discovery Protocol (CDP) is a Cisco proprietary protocol designed to help administrators collect information about local and remote devices. You can use the CDP to gather hardware and protocol information about neighbor devices. 问题 30 What is the maximum numbe