最新CCNA第一学期第八章答案

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思科CCNA1第八章试题及答案英文版

思科CCNA1第八章试题及答案英文版

1. 1. QuestionWhat is a result of connecting two or more switches together?o The number of broadcast domains is increased.o The size of the broadcast domain is increased.o The number of collision domains is reduced.o The size of the collision domain is increased.2. 2. QuestionRefer to the exhibit. How many broadcast domains are there?CCNA1 v6.0 Chapter 8 Exam 005o 1o 2o 3o43. 3. QuestionWhat are two reasons a network administrator might want to create subnets?(Choose two.)o simplifies network designo improves network performanceo easier to implement security policieso reduction in number of routers neededo reduction in number of switches needed4. 4. QuestionRefer to the exhibit. A company uses the address block of 128.107.0.0/16 for its network. What subnet mask would provide the maximum number of equal size subnets while providing enough host addresses for each subnet in the exhibit?CCNA1 v6.0 Chapter 8 Exam 007o 255.255.255.0o 255.255.255.128o 255.255.255.192o 255.255.255.224o 255.255.255.2405. 5. QuestionRefer to the exhibit. The network administrator has assigned the LAN of LBMISS an address range of 192.168.10.0. This address range has beensubnetted using a /29 prefix. In order to accommodate a new building, the technician has decided to use the fifth subnet for configuring the newnetwork (subnet zero is the first subnet). By company policies, the router interface is always assigned the first usable host address and the workgroup server is given the last usable host address. Which configuration should be entered into the properties of the workgroup server to allow connectivity to the Internet?CCNA1 v6.0 Chapter 8 Exam 004o IP address: 192.168.10.65 subnet mask: 255.255.255.240, default gateway: 192.168.10.76o IP address: 192.168.10.38 subnet mask: 255.255.255.240, default gateway: 192.168.10.33o IP address: 192.168.10.38 subnet mask: 255.255.255.248, default gateway: 192.168.10.33o IP address: 192.168.10.41 subnet mask: 255.255.255.248, default gateway: 192.168.10.46o IP address: 192.168.10.254 subnet mask: 255.255.255.0, defaultgateway: 192.168.10.16. 6. QuestionIf a network device has a mask of /28, how many IP addresses are available for hosts on this network?o 256o 254o 62o 32o 16o 147. 7. QuestionWhich subnet mask would be used if 5 host bits are available?o 255.255.255.0o 255.255.255.128o 255.255.255.224o 255.255.255.2408. 8. QuestionHow many host addresses are available on the network 172.16.128.0 with a subnet mask of 255.255.252.0?o 510o 512o1022o 1024o 2046o 20489. 9. QuestionHow many bits must be borrowed from the host portion of an address to accommodate a router with five connected networks?o twoo threeo fouro five10. 10. QuestionA network administrator wants to have the same network mask for allnetworks at a particular small site. The site has the following networks and number of devices:IP phones – 22 addressesPCs – 20 addresses neededPrinters – 2 addresses neededScanners – 2 addresses neededThe network administrator has deemed that 192.168.10.0/24 is to be the network used at this site. Which single subnet mask would make the most efficient use of the available addresses to use for the four subnetworks?o 255.255.255.0o 255.255.255.192o 255.255.255.224o 255.255.255.240o 255.255.255.248o 255.255.255.25211. 11. QuestionA company has a network address of 192.168.1.64 with a subnet mask of255.255.255.192. The company wants to create two subnetworks that would contain 10 hosts and 18 hosts respectively. Which two networks wouldachieve that? (Choose two.)o 192.168.1.16/28o 192.168.1.64/27o 192.168.1.128/27o 192.168.1.96/28o 192.168.1.192/2812. 12. QuestionA network administrator is variably subnetting a network. The smallestsubnet has a mask of 255.255.255.248. How many usable host addresses will this subnet provide?o 4o 6o 8o 10o 1213. 13. QuestionRefer to the exhibit. Given the network address of 192.168.5.0 and a subnet mask of 255.255.255.224 for all subnets, how many total host addresses are unused in the assigned subnets?CCNA1 v6.0 Chapter 8 Exam 001o 56o 60o 64o 68o7214. 14. QuestionRefer to the exhibit. Considering the addresses already used and having to remain within the 10.16.10.0/24 network range, which subnet address could be assigned to the network containing 25 hosts?CCNA1 v6.0 Chapter 8 Exam 002o 10.16.10.160/26o 10.16.10.128/28o 10.16.10.64/27o 10.16.10.224/26o 10.16.10.240/27o 10.16.10.240/2815. 15. QuestionA network administrator needs to monitor network traffic to and fromservers in a data center. Which features of an IP addressing scheme should be applied to these devices?o random static addresses to improve securityo addresses from different subnets for redundancyo predictable static IP addresses for easier identificationo dynamic addresses to reduce the probability of duplicate addresses 16. 16. QuestionWhich two reasons generally make DHCP the preferred method of assigning IP addresses to hosts on large networks? (Choose two.)o It eliminates most address configuration errors.o It ensures that addresses are only applied to devices that require apermanent address.o It guarantees that every device that needs an address will get one.o It provides an address only to devices that are authorized to be connected to the network.o It reduces the burden on network support staff.17. 17. QuestionA DHCP server is used to assign IP addresses dynamically to the hosts on anetwork. The address pool is configured with 192.168.10.0/24. There are 3 printers on this network that need to use reserved static IP addresses from the pool. How many IP addresses in the pool are left to be assigned to other hosts?o 254o251o 252o 25318. 18. QuestionRefer to the exhibit. A company is deploying an IPv6 addressing scheme for its network. The company design document indicates that the subnet portion of the IPv6 addresses is used for the new hierarchical network design, with the s ite subsection to represent multiple geographical sites of the company, the s ub-site section to represent multiple campuses at each site, and thes ubnet section to indicate each network segment separated by routers. With such a scheme, what is the maximum number of subnets achievedper sub-site?CCNA1 v6.0 Chapter 8 Exam 003o 0o 4o16o 25619. 19. QuestionWhat is the prefix for the host address 2001:DB8:BC15:A:12AB::1/64?o 2001:DB8:BC15o 2001:DB8:BC15:Ao 2001:DB8:BC15:A:1o 2001:DB8:BC15:A:1220. 20. QuestionConsider the following range of addresses:2001:0DB8:BC15:00A0:0000::2001:0DB8:BC15:00A1:0000::2001:0DB8:BC15:00A2:0000::…2001:0DB8:BC15:00AF:0000::The prefix-length for the range of addresses is /6021. 21. QuestionMatch the subnetwork to a host address that would be included within the subnetwork. (Not all options are used.)CCNA1 v6.0 Chapter 8 Exam 0122. 22. QuestionRefer to the exhibit. Match the network with the correct IP address and prefix that will satisfy the usable host addressing requirements for each network. (Not all options are used.)CCNA1 v6.0 Chapter 8 Exam 006。

完整版CCNA测试题库及答案

完整版CCNA测试题库及答案

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。

最新 CCNA第二学期章节测试 第八章 答案

最新 CCNA第二学期章节测试  第八章 答案

参加考试- ERouting Chapter 8 - CCNA Exploration: 路由协议和概念(版本 4.0) 1请参见图示。

下列哪项陈述能够正确描述该网络?错误!未找该网络使用EIGRP到引用源。

错误!未找至少包含一条父路由和一条子路由到引用源。

错误!未找192.168.2.0、192.168.3.0 和192.168.4.0 网络是子路由到引用源。

错误!未找发往172.16.3.0 的流量将被引导至s 0/0/1到引用源。

2请参见图示。

路由器 B 接收到目的地址为10.16.1.97 的数据包。

路由器 B 将会做什么?错误!未找丢弃数据包到引用源。

错误!未找使用默认路由到引用源。

错误!未找通过到10.16.1.0 的路由转发该数据包到引用源。

错误!未找通过到10.16.1.64 的路由转发该数据包到引用源。

3请参见图示。

Router1 将对172.16.0.0/24 网络的子路由应用什么子网掩码?错误!未找0.0.0.0到引用源。

错误!未找255.255.0.0到引用源。

错误!未找255.255.255.0到引用源。

错误!未找255.255.255.255到引用源。

4请参见图示。

Router1 正在运行IOS 第12.2 版。

网络管理员需要做什么工作才能确保发往172.16.0.0/24 未知子路由的数丢弃?错误!未找使用ip default-network命令到引用源。

错误!未找使用RIPv1 之类的有类路由协议到引用源。

错误!未找启用OSPF 或ISIS 作为路由协议到引用源。

错误!未找使用ip classless命令到引用源。

错误!未找什么都不用做,默认会启用ip classless到引用源。

5路由表中显示以下条目:R 192.168.8.0/24 [120/2] via 192.168.4.1, 00:00:26, Serial0/0/1这是哪种类型的路由?错误!未找1 级父路由到引用源。

CCNA认证基础课程-课后作业.习题答案

CCNA认证基础课程-课后作业.习题答案

CCNA认证基础-习题分析讲义第一部分第一章1. Convert the binary number 10111010 into its hexadecimal equivalent. Select thecorrect answer from the list below. (3)1) 852) 903) BA4) A15) B36) 1C2. Convert the Hexadecimal number A2 into its Base 10 equivalent. Select thecorrect answer from the list below. (4)1) 1562) 1583) 1604) 1625) 1646) 1663. Which binary number is a representation of the decimal number 248? (3)1) 111010002) 111101003) 111110004) 111110104. Which of the following will test the internal loopback of a node? (3)1) ping 10.10.10.12) ping 192.168.1.13) ping 127.0.0.14) ping 223.223.223.2235) ping 255.255.255.2555. What can be verified by successfully pinging the reserved loopback address ona host? (2)1) Connectivity exists between two hosts on the LAN.2) The TCP/IP stack of the local host is configured correctly.3) A connection exists between a host and the default gateway.4) The route a packet takes from the local host to a remote host is valid.6. Which of the following commands could be used on a Windows-basedcomputer to view the current IP configuration of the system? (Choose two.) (3,4)1) configip2) ifconfig3) ipconfig4) winipcfg5) Winipconfig7.Refer to the exhibit. What must be configured on Host B to allow it to communicate withthe Host C? (Choose three.) (2,4,6)1)the MAC address of RTA router interface connected to Switch 12) a unique host IP address3)the IP address of Switch 14)the default gateway address5)the MAC address of Host C6)the subnet mask for the LAN8. What are important characteristics to consider when purchasing a networkinterface card? (Choose two.) (2,3)1) security used on the network2) media used on the network3) system bus used on the computer4) software installed on the network5) diagnostic tools installed on the network第二章1. Select the necessary information that is required to compute the estimated timeit would take to transfer data from one location to another. (Choose two.) (1,5)1) file size2) data format3) network in use4) type of medium5) bandwidth of the link2. Using the data transfer calculation T=S/BW, how long would it take a 4MB file tobe sent over a 1.5Mbps connection? (2)1) 52.2 seconds2) 21.3 seconds3) 6.4 seconds4) 2 seconds5) 0.075 seconds6) 0.0375 seconds3. What are features of the TCP/IP Transport layer? (Choose two.) (3,5)1) path determination2) handles representation, encoding and dialog control3) uses TCP and UDP protocols4) packet switching5) reliability, flow control and error correction4. Which of the following is the Layer 4 PDU? (4)1) bit2) frame3) packet4) Segment5. What is important to remember about the data link layer of the OSI model whenconsidering Peer to Peer communication? (Choose three.) (3,4,5)1) It links data to the transport layer.2) It encapsulates frames into packets.3) It provides a service to the network layer.4) It encapsulates the network layer information into a frame.5) Its header contains a physical address which is required to complete the datalink functions.6) It encodes the data link frame into a pattern of 1s and 0s (bits) for transmissionon the medium.6. Which statement describes a star topology? (2)1) Each host in the network is connected to a backbone cable that is terminated atboth ends.2) Each host is connected to a hub or switch, either of which acts as a central pointfor all network connections.3) Each host is directly connected to two other hosts to form a long chain of hosts.4) Each host has a connection to all other hosts in the network.7. Which statements describe the logical token-passing topology? (Choose two.)(2)1) Network usage is on a first come, first serve basis.2) Computers are allowed to transmit data only when they possess a token.3) Data from a host is received by all other hosts. Electronic tokens are passedsequentially to each other.4) Token passing networks have problems with high collision rates.8. Which technologies are considered to be LAN technologies? (Choose two.) (2,5)1) DSL2) Token Ring3) Frame Relay4) ISDN5) Ethernet9.Refer to the exhibit. Host A wants to send a message to host B. Place the following stepsin the correct order so that the message can be sent. (4)A - add network layer addressesB - transmit bitsC - create application dataD - add data link layer addresses1) B, A, D, C2) D, A, C, B3) A, D, A, B4) C, A, D, B5) C, D, A, B6) C, B, A, D10.After an uns u ccessful ping to the local router, the technician decides to investigate therouter. The technician observes that the lights and fan on the router are not operational.In which layer of the OSI model is the problem most likely occurring? (4)1) transport2) network3) data link4) physical11. Refer t o the exhibit. What is the order of the TCP/IP Protocol Data Units as datais moved as indicated through the OSI model? (3)1) data, segments, frames, packets, bits2) data, packets, segments, frames, bits3) data, segments, packets, frames, bits4) data, packets, frames, segments, bits第三章1. Which combinations of charges will be repelled by electric force? (Choose two.)(4,6)1) neutral and neutral2) neutral and positive3) neutral and negative4) positive and positive5) positive and negative6) negative and negative2. Which of the following are considered the best media for use in data networkcommunications? (Choose three.) (2,3,6)1) glass2) fibers3) copper4) gold5) plastic6) silicon7) Silver3. Which of the following wireless standards increased transmission capabilitiesto 11 Mbps? (2)1) 802.11a2) 802.11b3) 802.11c4) 802.11d4. What is attenuation? (3)1) opposition to the flow of current2) measurement of electrical signals relative to time3) degradation of a signal as it travels along the medium4) amount or volume of traffic that is flowing on the medium5. Which cable specifications are indicated by 10BASE-T? (3)1) 10 Mbps transmission speed, baseband signal, 500 meter cable length, coaxialcable2) 10 Mbps transmission speed, broadband signal, 100 meter cable length, coaxialcable3) 10 Mbps transmission speed, baseband signal, 100 meter cable length,twisted-pair cable4) 10 Gbps transmission speed, broadband signal, 500 meter cable length,twisted-pair cable6. For which Ethernet installations would fiber optic rather than Cat5 UTP be abetter media choice? (Choose two.) (2,4)1) a 3 meter connection between two 10BASE-T hubs2) an environment with many potential sources of EMI and RFI3) a peer to peer connection between two NICs with RJ45 connectors4) an installation between two buildings that are located 500 meters apart5) a single building installation where installation costs are the major concern7. Refer to the exhibit. Which type of UTP cable should be used to connect Host Ato Switch1? (4)1) rollover2) console3) crossover4) straight-through8. Refer to the exhibit. Which type of Category 5 cable is used to make an Ethernetconnection between Host A and Host B? (3)1) coax cable2) rollover cable3) crossover cable4) straight-through cable第四章1. During cable testing, which of the following are used to calculate theinformation carrying capacity of a data cable? (Choose two.) (2,5)1) bit speed2) attenuation3) wire map4) saturation limit5) analog bandwidth2. What type of wiring problem is depicted in this sample of a cable tester? (3)1) a fault2) a short3) an open4) a split a good map3. In a new network installation, the network administrator has decided to use amedium that is not affected by electrical noise. Which cable type will best meet this standard? (5)1) coaxial2) screened twisted pair3) shielded twisted pair4) unshielded twisted pair5) fiber optic4. How does network cable length affect attenuation? (3)1) Category 5 cable that is run in metal conduit has the highest attenuation in theshortest distance.2) Shorter cable lengths have greater signal attenuation.3) Longer cable lengths have greater signal attenuation.4) The length of the cable has no effect on signal attenuation.第五章1. The highest capacity Ethernet technologies should be implemented in whichareas of a network? (Choose three.) (3,4,5)1) between workstation and backbone switch2) between individual workstations3) between backbone switches4) between enterprise server and switch5) on aggregate access links2. What device must be used between an AUI port of a networking device and themedia to which it is being connected? (3)1) a transducer2) a transmitter3) a transceiver4) a transponder5) a port replicator3. An ISDN Basic Rate Interface (BRI) is composed of how many signalingchannels? (1)1) 12) 23) 34) 44. Which layer of the OSI model covers physical media? (1)1) Layer 12) Layer 23) Layer 34) Layer 45) Layer 56) Layer 65. What type of network cable is used between a terminal and a console port? (3)1) cross-over2) straight-through3) rollover4) patch cable6. What is the recommended maximum number of workstations configured on apeer-to-peer network? (3)1) 252) 153) 104) 55) 27. Which of the following increases the potential for a collision to occur? (4)1) the use of an active hub instead of an intelligent hub2) the use of an intelligent hub instead of an active hub3) a reduction in the number of devices attached to the hub4) an increase in the number of devices attached to the hub8. What is the maximum length of a media segment used for 100BASE-TX? (1)1) 100 meters2) 185 meters3) 400 meters4) 500 meters9. Which cable diagram displays the end to end pinout for a crossover cable usedwith Cisco devices? (3)1) Cable A2) Cable B3) Cable C4) Cable D第六章1. What does the "10" in 10Base2 indicate about this version of Ethernet? (2)1) The version uses Base10 numbering within the frames.2) The version operates at a transmission rate of 10 Mbps.3) Frames can travel 10 meters unrepeated.4) The maximum frame length is 10 octets.2. How is a MAC address represented? (4)1) four groups of eight binary digits separated by a decimal point2) four Base10 digits separated by a decimal point3) six hexadecimal digits4) twelve hexadecimal digits5) twenty-four Base10 digits3. Which of the following statements are correct about CSMA/CD? (Choose three.)(1,3,6)1) It is a media access method used in LANs.2) It is a media access method used in FDDI WANs.3) When a device needs to transmit, it checks to see if the media is available.4) A device sends data without checking media availability because all deviceshave equal access.5) Multiple devices can successfully transmit simultaneously.6) Only one device can successfully transmit at a time.4. Which devices shown in the graphic must have a MAC address? (5)1) only PC2) only router3) PC and router4) PC, hub, and router5) PC, printer, and router第七章1. Which of the following items are common to all 100BASE technologies?(Choose three.) (1,4,5)1) frame format2) media3) connectors4) timing5) multi-part encoding2. Which of the following does 1000BASE-T use to accomplish gigabit speeds onCat 5e cable? (4)1) the use of four conductors in full-duplex mode2) the use of two multiplexed pairs of wires, simultaneously3) the use of three pairs of wires for data and the fourth for stabilization andforward error correction4) the use of all four pairs of wires in full-duplex mode, simultaneously3. For which of the following is Ethernet considered the standard? (Choose three.)(1,4,5)1) inter-building connection2) mid-length voice3) video conferencing4) vertical wiring5) horizontal wiring6) diagonal wiring4. To make sure timing limitations are not violated when implementing a 10 MbpsEthernet network involving hubs or repeaters, a technician should adhere to which rule? (4)1) the 4-5-3 rule2) the 6-4-2 rule3) the 3-4-5 rule4) the 5-4-3 rule5. What is the maximum distance that 10BASE-T will transmit data before signalattenuation affects the data delivery? (1)1) 100 meters2) 185 meters3) 300 meters4) 500 meters6. When using Category 5 UTP cable, which RJ-45 pin pairs are used to exchangedata between hosts on an Ethernet network? (2)1) 1 and 2; 4 and 52) 1 and 2; 3 and 63) 3 and 6; 7 and 84) 4 and 5; 7 and 8第八章1. John has been hired as the network administrator of a local company and hasdecided to add more hubs to the company's existing network. Which of the following has been caused by John's inexperience? (1)1) collision domain extended2) an increased number of collision domains3) increased network performance4) increased bandwidth5) extended bandwidth2. "CompA" is trying to locate a new computer named "CompB" on the network.Which of the following does "CompA" broadcast to find the MAC address of "CompB"? (2)1) MAC request2) ARP request3) ping4) Telnet5) proxy ARP3. Which of the following is a term associated with replacing hubs with switchesto increase the number of collision domains? (3)1) encapsulation2) latency3) segmentation4) layered model5) broadcast domain6) Extended4. The accumulation of traffic from which of the following can cause a networkcondition called broadcast radiation? (Choose three.) (3,5,6)1) anonymous FTP servers2) telnet sessions3) video over IP applications4) NAS services5) ARP requests6) RIP updates5. Which of the following describes the use of Spanning Tree Protocol (STP)? (4)1) resolve routing loops2) eliminate Split Horizon errors3) limit collisions4) resolve switching loops6. Which term describes the delay in time that occurs when a frame leaves itssource device and reaches its destination? (4)1) collision2) backoff3) attenuation4) latency5) broadcast7. Based on the graphic above, which of the following occurs as each host systemcomes on line in the topology? (2)1) The switch sends its MAC address to each host.2) The switch adds MAC address to the bridge table as each host sends a frame.3) Each host exchanges MAC addresses with each other.4) The switch listens for data traffic to block since the switch lacks an IP address. 8. Which devices segment collision domains? (Choose two.) (2,3)1) transceiver2) router3) switch4) hub5) media9. Which protocol is used to eliminate switching loops? (3)1) Transmission Control Protocol2) Routing Information Protocol3) Spanning Tree Protocol4) Interior Gateway Routing Protocol5) Internetworking Protocol10. Refer to the exhibit. A network associate needs to establish an Ethernetconnection between Host A and Host B. However, the distance between the two hosts is further than the cabling standards allow. Which two devices that operate at the physical layer of the OSI can be used to allow Host A and Host B to communicate? (2,5)1) switch2) hub3) bridge4) router5) repeater第九章1. Which term describes an ARP response by a router on behalf of a requestinghost? (3)1) ARP2) RARP3) Proxy ARP4) Proxy RARP2. Which protocol functions at the internet layer of the TCP/IP protocol suite? (4)1) File Transfer Protocol (FTP)2) Trivial File Transfer Protocol (TFTP)3) Transmission Control Protocol (TCP)4) Internet Protocol (IP)5) User Datagram Protocol (UDP)6) Simple Mail Transport Protocol (SMTP)3. Which of these workstation installation and setup tasks are concerned withnetwork access layer functions? (Choose two.) (2,4)1) configuring the e-mail client2) installing NIC drivers3) configuring IP network settings4) connecting the network cable5) using FTP to download application software updates4. Which part of an IP address identifies a specific device on a network? (4)1) first two octets2) third and fourth octets3) network portion4) host portion5) only the fourth octet5. Which of the following are features of the Internet Protocol (IP)? (Choose two.)(1,3)1) It is the most widely implemented global addressing scheme.2) It allows two hosts to share a single address on a local area network.3) It is a hierarchical addressing scheme allowing addresses to be grouped.4) It is only locally significant, used primarily on local area networks.6. Which of the following are useable Class A IP addresses with a default subnetmask? (Choose three.) (2,3,5)1) 127.0.39.12) 111.9.28.303) 123.1.2.1324) 128.50.38.25) 105.1.34.16) 0.23.92.37. Which application layer protocols use UDP at the transport layer? (Choose two.)(2,4)1) FTP2) SNMP3) Telnet4) DHCP5) SMTP第十章1. Which OSI layer encapsulates data into packets? (3)1) session2) transport3) network4) data link2. Which OSI layer defines the functions of a router? (3)1) physical2) data link3) network4) transport5) session3. Which of the following are Cisco proprietary routing protocols? (Choose two.)(2,6)1) RIPv22) IGRP3) OSPF4) BGP5) RIPv16) EIGRP4. A company with a Class B license needs to have a minimum of 1,000 subnetswith each subnet capable of accommodating 50 hosts. Which mask below is the appropriate one? (4)1) 255.255.0.02) 255.255.240.03) 255.255.255.04) 255.255.255.1925) 255.255.255.2245. A small company has a class C network license and needs to create five usablesubnets, each subnet capable of accommodating at least 20 hosts. Which of the following is the appropriate subnet mask? (3)1) 255.255.255.02) 255.255.255.1923) 255.255.255.2244) 255.255.255.2406. When a network administrator applies the subnet mask 255.255.255.248 to aClass A address, for any given subnet, how many IP addresses are available to be assigned to devices? (6)1) 10222) 5103) 2544) 1265) 306) 67. Host A is assigned the IP address 10.18.97.55 /21. How many more networkdevices can be assigned to this subnetwork if Host A is the only one that has an IP address assigned so far? (4)1) 2542) 5093) 10214) 20455) 40946) 81908.Refe r to the exhibit. The network administrator wants to create a subnet for thepoint-to-point connection between the two routers. Which subnetwork mask would provide enough addresses for the point-to-point link with the least number of wasted addresses?1) 255.255.255.1922) 255.255.255.2243) 255.255.255.2404) 255.255.255.2485) 255.255.255.2529. What is the correct number of usable subnetworks and hosts for the IP networkaddress 192.168.35.0 subnetted with a /28 mask?1) 6 networks / 64 hosts2) 14 networks / 32 hosts3) 14 networks / 14 hosts4) 30 networks / 64 hosts10. Which subnet masks would be valid for a subnetted Class B address? (Choosetwo.) (5,6)1) 255.0.0.02) 255.254.0.03) 255.224.0.04) 255.255.0.05) 255.255.252.06) 255.255.255.19211. Refer to the exhibit. How will the Fohi router dynamically learn routes to the192.168.16.16/28, 192.168.16.32/28, and 192.168.16.48/28 subnetworks? (3)1) with a static route2) with a routed protocol3) with a routing protocol4) with a directly connected route12. How many broadcast domains are shown in the diagram? (1)1) three2) four3) five4) six5) seven6) eight13. How many collision domains are shown in the diagram? (5)1) three2) four3) five4) six5) seven6) eight14. A router interface has been assigned an IP address of 172.16.192.166 with amask of 255.255.255.248. To which subnet does the IP address belong?1) 172.16.0.02) 172.16.192.03) 172.16.192.1284) 172.16.192.1605) 172.16.192.1686) 172.16.192.17615. Refer to the exhibit. Host A is sending data to Host B. Once R2 determines thatdata from Host A must be forwarded to R1 to reach Host B, which layer of the OSI model will R2 use to address and build the frames destined for R1?1) physical2) data link3) network4) transport5) session6) presentation16. Which type of address is 192.168.170.112/28?1) host address2) subnetwork address3) broadcast address4) multicast address17. Which type of address is 223.168.17.167/29?1) host address2) multicast address3) broadcast address4) subnetwork address18. Which combination of network id and subnet mask correctly identifies all IPaddresses from 172.16.128.0 through 172.16.159.255?1) 172.16.128.0 255.255.255.2242) 172.16.128.0 255.255.0.03) 172.16.128.0 255.255.192.04) 172.16.128.0 255.255.224.05) 172.16.128.0 255.255.255.19219. Refer to the exhibit. The internetwork in the exhibit has been assigned the IPaddress 172.20.0.0. What would be the appropriate subnet mask to maximize the number of networks available for future growth?1) 255.255.224.02) 255.255.240.03) 255.255.248.04) 255.255.252.05) 255.255.254.06) 255.255.255.0第十一章1. If a network administrator needed to download files from a remote server, whichprotocols could the administrator use to remotely access those files? (Choose two.) (3,5)1) NFS2) ASCII3) TFTP4) IMAP5) FTP6) UDP2. What is established during a connection-oriented file transfer betweencomputers? (Choose two.) (2,5)1) a temporary connection to establish authentication of hosts2) a connection used for ASCII or binary mode data transfer3) a connection used to provide the tunnel through which file headers aretransported4) a command connection which allows the transfer of multiple commands directlyto the remote server system5) a control connection between the client and server3. Which of the following protocols are used for e-mail transfer between clientsand servers? (Choose three.) (3,4,5)1) TFTP2) SNMP3) POP34) SMTP5) IMAP46) postoffice4. Which type of institution does the domain suffix .org represent? (4)1) government2) education3) network4) non-profit5. Which of the following services is used to translate a web address into an IPaddress? (1)1) DNS2) WINS3) DHCP4) Telnet6. Which part of the URL http://www.awsb.ca/teacher gives the name of thedomain? (4)1) www2) http://3) /teacher4) awsb.ca7. Which protocols are TCP/IP application layer protocols? (Choose two.) (2,4)1) UDP2) FTP3) IP4) SMTP5) TCP8. What are three characteristics of the TCP protocol? (Choose three.) (3,4,6)1) has less overhead than UDP2) is used for IP error messages3) forces the retransmission undelivered packets4) creates a virtual session between end-user applications5) carries the IP address of destination host in the TCP header6) is responsible for breaking messages into segments and reassembling9. Two peer hosts are exchanging data using TFTP. During the current session, adatagram fails to arrive at the destination. Which statement is true regarding the retransmission of the datagram? (2)1) Datagram retransmission requires user authentication.2) Datagram retransmission is controlled by the application.3) Datagram retransmission relies on the acknowledgements at transport layer.4) Datagram retransmission occurs when the retransmission timer expires in thesource host.案例学习1. 子网计算练习:Answer2. 子网号及广播地址计算练习Answer3. 子网规划练习:已知:给定一个C类地址201.16.5.0/24。

CCNA认证试题(中文+答案)

CCNA认证试题(中文+答案)

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及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 (1 72.16/12 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。

CCNA认证试题(中文+答案)

CCNA认证试题(中文+答案)

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。

最新CCNA题库 V102上卷(含答案无水印)

最新CCNA题库 V102上卷(含答案无水印)

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?。

2023年CCNA考试真题答案分析

2023年CCNA考试真题答案分析

2023年CCNA考试真题答案分析作为全球性的IT认证考试之一,CCNA(Cisco Certified Network Associate)考试一直以来都备受关注。

2023年CCNA考试的真题是许多考生关注的焦点。

下面将对2023年CCNA考试的真题答案进行分析,旨在帮助考生更好地了解考试的内容和要求。

一、第一题:在OSPF协议中,下面哪个区域是Stub区域?答案:区域0(Area 0)分析:OSPF(Open Shortest Path First)是一种广泛使用的内部网关协议(IGP)。

在OSPF中,区域被用于划分网络,Stub区域是指一个没有外部路由进入的区域。

在OSPF中,区域0通常被称为Backbone区域,是所有其他区域的集线器。

因此,区域0是Stub区域。

二、第二题:在TCP/IP协议栈中,下面哪个协议负责将IP地址转换为MAC地址?答案:ARP(Address Resolution Protocol)分析:ARP是一种用于将IP地址转换为MAC地址的协议,它工作在TCP/IP协议栈的网络层和数据链路层之间。

当一个主机需要发送数据包到目标主机时,它首先会查询ARP缓存表,如果找不到目标主机的MAC地址,则会发送ARP请求广播,请求目标主机回应其MAC地址。

三、第三题:在VLAN中,下面哪个协议用于实现不同VLAN之间的通信?答案:路由协议或三层交换机分析:VLAN(Virtual Local Area Network)是一种实现逻辑隔离的技术,可以将物理上的网络划分为多个逻辑上的网络。

不同VLAN之间的通信需要通过路由器或三层交换机来实现。

路由器可以实现不同VLAN之间的互联,而三层交换机具备路由功能,可以在交换机内部实现不同VLAN之间的通信。

四、第四题:以下哪种网络攻击会使用大量的伪造的IP数据包来淹没目标网络?答案:DDoS(Distributed Denial of Service)分析:DDoS是一种分布式拒绝服务攻击,攻击者会利用多个主机发送大量的伪造IP数据包到目标网络,造成网络堵塞、服务不可用等问题。

2016CCNA1各章及期末考试答案

2016CCNA1各章及期末考试答案

ITN 第7 章考试1什么是套接字?正确响应您的响应源和目的IP 地址以及源和目的以太网地址的组合源IP 地址与端口号的组合或目的IP 地址与端口号的组合源和目的序列号和确认号的组合源和目的序列号和端口号的组合套接字是源IP 地址与源端口号的组合,或者目的IP 地址与目的端口号的组合。

此试题参考以下领域的内容:Introduction to Networks•7.1.2 TCP 和UDP 简介2主机设备需要通过网络发送大型视频文件,同时为其他用户提供数据通信。

下列哪种功能可以让不同通信流同时发生,而不会让一个数据流使用所有可用带宽?正确响应您的响应窗口大小多路复用端口号确认多路复用对交替发送多个通信流很有用。

窗口大小用于降低数据通信速率。

端口号用于将数据流传送到正确的应用程序。

确认用于通知发送设备数据包流已收到或未收到。

此试题参考以下领域的内容:Introduction to Networks•7.1.1 数据传输3主机设备通过HTTP 协议向Web 服务器发送数据包。

传输层使用下列哪项来将数据流传送到服务器上的正确应用程序?正确响应您的响应序列号确认源端口号目的端口号目的端口号用于将数据流传输到正确的应用程序,而源端口号由源设备随机生成并进行跟踪。

序列号用于指示如何重组和重新排序收到的数据段。

确认用于通知发送设备数据包流已收到或未收到。

此试题参考以下领域的内容:Introduction to Networks•7.1.1 数据传输4UDP 传输协议有什么有利功能?正确响应您的响应确认已接收的数据减少传输延迟使用序列号跟踪数据段能够重新传输丢失的数据由于其报头小于TCP 报头,UDP 协议可以减少传输延迟。

此试题参考以下领域的内容:Introduction to Networks•7.1.1 数据传输5下列哪种场景描述了传输层提供的功能?正确响应您的响应学生使用教室里的VoIP 电话给家里打电话。

CCNA第一学期各章习题及答案

CCNA第一学期各章习题及答案

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002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006请参见图示。

所示网络属于哪一类型WANMANLANWLAN007 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009 请参见图示。

下列哪组设备仅包含终端设备A、C、DB、E、G、HC、D、G、H、I、JD、E、F、H、I、JE、F、H、I、J010 选择关于网络协议的正确陈述。

CCNA第一学期Finalexam考试英文版答案

CCNA第一学期Finalexam考试英文版答案

CCNA第一学期Finalexam考试英文版答案(R&S.)C 1A medium-sized business is researching available options for connecting to the Internet.Thecompany is looking for a high speed option with dedicated, symmetric access.Whichconnection type should the company choose?DSLdialupsatelliteleased linecable modem2What is the purpose of having a converged network?to provide high speed connectivity to all end devicesto make sure that all types of data packets will be treated equallyto achieve fault tolerance and high availability of data network infrastructure devicesto reduce the cost of deploying and maintaining thecommunication infrastructure3What characteristic of a network enables it to quickly grow to support new users andapplications without impacting the performance of the service being delivered to existing users?reliabilityscalabilityquality of serviceaccessibility4Which connection provides a secure CLI session with encryption to a Cisco switch?a console connectionan AUX connectiona Telnet connectionan SSH connection5A network technician is attempting to configure an interface by entering the followingcommand:SanJose(config)#ip address192.168.2.1255.255.255.0.The command isrejected by the device.What is the reason for this? The command is being entered from the wrong mode of operation.The command syntax is wrong.The subnet mask information is incorrect.The interface is shutdown and must be enabled before the switch will accept the IP address.6After several configuration changes are made to a router, the copy running-configurationstartup-configuration command is issued.Where will the changes be stored?flashROMNVRAMRAMthe configuration registera TFTP server7Refer to the exhibit.From global configuration mode,an administrator is attempting to create a message-of-the-day banner by using thecommand banner motd V Authorized access only!Violators will be prosecuted!V When users log in using Telnet,the banner does not appear correctly.What is the problem? The banner message is too long.The delimiting character appears in the banner message.The symbol“!”signals the end of a banner message.Message-of-the-day banners will only appear when a user logs in through the console port.8What are three characteristics of an SVI?(Choose three.) It is designed as a security protocol to protect switch ports.It is not associated with any physical interface on a switch.It is a special interface that allows connectivity by different types of media.It is required to allow connectivity by any device at any location.It provides a means to remotely manage a switch.It is associated with VLAN1by default.9A technician configures a switch with these commands: SwitchA(config)#interface vlan1SwitchA(config-if)#ip address192.168.1.1255.255.255.0 SwitchA(config-if)#no shutdownWhat is the technician configuring?Telnet accessSVIpassword encryptionphysical switchport access10In computer communication,what is the purpose of message encoding?to convert information to the appropriate form for transmissionto interpret informationto break large messages into smaller framesto negotiate correct timing for successful communication11What protocol is responsible for controlling the size of segments and the rate at whichsegments are exchanged between a web client and a web server?TCPIPHTTPEthernet12What are two benefits of using a layered network model? (Choose two.)It assists in protocol design.It speeds up packet delivery.It prevents designers from creating their own model.It prevents technology in one layer from affecting other layers.It ensures a device at one layer can function at the next higher layer.13What is the process of dividing a data stream into smaller pieces before transmission?segmentationencapsulationencodingflow control14When IPv4addressing is manually configured on a web server,which property of the IPv4configuration identifies the network and host portion for an IPv4address?DNS server addresssubnet maskdefault gatewayDHCP server address15A network administrator is troubleshootingconnectivity issues on a ing a tester,the administrator notices that the signals generated by the server NIC are distorted and not usable.In which layer of the OSI model is the error categorized?presentation layernetwork layerphysical layerdata link layer16A network engineer is measuring the transfer of bits across the company backbone for amission critical database application.The engineer notices that the network throughputappears lower than the bandwidth expected.Which three factors could influence thedifferences in throughput?(Choose three.)the amount of traffic that is currently crossing the networkthe sophistication of the encapsulation method applied to the datathe type of traffic that is crossing the networkthe latency that is created by the number of network devices that the data is crossingthe bandwidth of the WAN connection to the Internetthe reliability of the gigabit Ethernet infrastructure of the backbone17Which type of UTP cable is used to connect a PC to a switch port?consolerollovercrossoverstraight-through18What is a characteristic of the LLC sublayer?It provides the logical addressing required that identifies the device.It provides delimitation of data according to the physical signaling requirements of the medium.It places information in the frame allowing multiple Layer 3protocols to use the same network interface and media.It defines software processes that provide services to the physical layer.19What are the three primary functions provided by Layer 2data encapsulation?(Choosethree.)error correction through a collision detection methodsession control using port numbersdata link layer addressingplacement and removal of frames from the mediadetection of errors through CRC calculationsdelimiting groups of bits into framesconversion of bits into data signals20What will a host on an Ethernet network do if it receives a frame with a destination MACaddress that does not match its own MAC address?It will discard the frame.It will forward the frame to the next host.It will remove the frame from the media.It will strip off the data-link frame to check the destination IP address.21What are two actions performed by a Cisco switch? (Choose two.)building a routing table that is based on the first IP address in the frame headerusing the source MAC addresses of frames to build and maintain a MAC address tableforwarding frames with unknown destination IP addresses to the default gatewayutilizing the MAC address table to forward frames via the destination MAC addressexamining the destination MAC address to add new entries to the MAC address table22What are two examples of the cut-through switching method?(Choose two.)store-and-forward switchingfast-forward switchingCRC switchingfragment-free switchingQOS switching23Refer to the exhibit.If host A sends an IP packet to host B,what will the destination address be in the frame when it leaves host A?DD:DD:DD:DD:DD:DD172.168.10.99CC:CC:CC:CC:CC:CC172.168.10.65BB:BB:BB:BB:BB:BBAA:AA:AA:AA:AA:AA24What are two services provided by the OSI network layer?(Choose two.)performing error detectionrouting packets toward the destinationencapsulating PDUs from the transport layerplacement of frames on the mediacollision detection25What information is added during encapsulation at OSI Layer3?source and destination MACsource and destination application protocolsource and destination port numbersource and destination IP address26What are two functions of NVRAM?(Choose two.)to store the routing tableto retain contents when power is removedto store the startup configuration fileto contain the running configuration fileto store the ARP table27Refer to the exhibit.The network administrator for a small advertising company has chosen to use the192.168.5.96/27 network for internal LAN addressing.As shown in the exhibit,a static IP address is assigned to the company web server.However,the web server cannot access the Internet.The administrator verifies that local workstations with IP addresses that are assigned by a DHCP server can access the Internet,and the web server is able to ping local workstations.Which component is incorrectly configured?subnet maskDNS addresshost IP addressdefault gateway address28Why does a Layer3device perform the ANDing process on a destination IP address andsubnet mask?to identify the broadcast address of the destination networkto identify the host address of the destination hostto identify faulty framesto identify the network address of the destination network29What are the three ranges of IP addresses that are reserved for internal private use?(Choosethree.)10.0.0.0/864.100.0.0/14127.16.0.0/12172.16.0.0/12192.31.7.0/24192.168.0.0/1630Which three addresses are valid public addresses? (Choose three.)198.133.219.17192.168.1.24510.15.250.5128.107.12.117192.15.301.24064.104.78.22731What type of IPv6address is FE80::1?loopbacklink-localmulticastglobal unicast32Refer to the exhibit.On the basis of the output,which two statements about network connectivity are correct? (Choose two.)There is connectivity between this device and the device at192.168.100.1.The connectivity between these two hosts allows for videoconferencing calls.There are4hops between this device and the device at 192.168.100.1.The average transmission time between the two hosts is2 milliseconds.This host does not have a default gateway configured.33Which subnet would include the address192.168.1.96as a usable host address?192.168.1.64/26192.168.1.32/27192.168.1.32/28192.168.1.64/2934How many hosts are addressable on a network that has a mask of255.255.255.248?268141625435Which statement is true about variable-length subnet masking?Each subnet is the same size.The size of each subnet may be different,depending on requirements.Subnets may only be subnetted one additional time.Bits are returned,rather than borrowed,to create additional subnets.36Refer to the exhibit.Consider the IP address of 192.168.10.0/24that has been assigned to a high school building.The largest network in this building has100 devices.If192.168.10.0is the network number for the largest network,what would be the network number for thenext largest network,which has40devices?192.168.10.0192.168.10.128192.168.10.192192.168.10.224192.168.10.24037In what two situations would UDP be the preferred transport protocol over TCP?(Choosetwo.)when applications need to guarantee that a packet arrives intact,in sequence,and unduplicatedwhen a faster delivery mechanism is neededwhen delivery overhead is not an issuewhen applications do not need to guarantee delivery of the datawhen destination port numbers are dynamic38What important information is added to the TCP/IPtransport layer header to ensurecommunication and connectivity with a remote network device?timing and synchronizationdestination and source port numbersdestination and source physical addressesdestination and source logical network addresses39What is the TCP mechanism used in congestion avoidance? three-way handshakesocket pairtwo-way handshakesliding window40Which three statements characterize UDP?(Choose three.)UDP provides basic connectionless transport layer functions.UDP provides connection-oriented,fast transport of data at Layer 3.UDP relies on application layer protocols for error detection.UDP is a low overhead protocol that does not provide sequencing or flow control mechanisms.UDP relies on IP for error detection and recovery.UDP provides sophisticated flow control mechanisms.41Which two tasks are functions of the presentation layer? (Choose two.)compressionaddressingencryptionsession controlauthentication42Which two protocols operate at the highest layer of the TCP/IP protocol stack?(Choose two.)DNSEthernetIPPOPTCPUDP43Which two roles can a computer assume in a peer-to-peer network where a file is beingshared between two computers?(Choose two.)clientmasterserverslavetransient44What is the function of the HTTP GET message?to request an HTML page from a web serverto send error information from a web server to a web clientto upload content to a web server from a web clientto retrieve client email from an email server using TCP port11045A wireless host needs to request an IP address.What protocol would be used to process therequest?FTPHTTPDHCPICMPSNMP46When planning for network growth,where in the network should packet captures take place toassess network traffic?on as many different network segments as possibleonly at the edge of the networkbetween hosts and the default gatewayonly on the busiest network segment47When applied to a router,which command would help mitigate brute-force password attacksagainst the router?exec-timeout30service password-encryptionbanner motd$Max failed logins=5$login block-for60attempts5within6048Refer to the exhibit.An administrator is testing connectivity to a remote device with the IP address10.1.1.1.What does the output of this command indicate?Connectivity to the remote device was successful.A router along the path did not have a route to the destination.A ping packet is being blocked by a security device along the path.The connection timed out while waiting for a reply fromthe remote device.。

ccna1章节与期末答案

ccna1章节与期末答案

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。

最新CCNA第一学期第八章答案

最新CCNA第一学期第八章答案

最新CCNA第一学期第八章答案最新CCNA第一学期第八章答案最新CCNA第一学期第八章答案IPv4 地址分为两个部分:网络部分- 用于识别主机所在的特定网络,主机部分- 用于识别网络中的特定主机。

子网掩码用于识别各个部分的长度。

255.255.255.224 的二进制格式为***-*****.***-*****.***-*****.***-*****。

前缀长度是掩码中连续的1 的个数。

因此,前缀长度为/27。

最新CCNA第一学期第八章答案定向广播是将消息发送到特定网络中的所有主机。

它适用于将广播发送到非本地网络中的所有主机。

组播消息是将消息发送到订阅组播组中的一组选定主机。

有限广播只限于将消息发送到本地网络中的主机。

单播消息是将消息从一台主机发送到另一台主机。

许多协议使用广播,因此无法避免。

路由器不转发广播,因此会在其每个接口形成一个广播域。

IPv6 中没有广播。

如果交换机收到广播数据包,它将通过除入站接口以外的所有接口转发此数据包。

6、DHCP 服务器用于为网络上的主机动态分配IP 地址。

地址池配置为192.168.10.0/24。

该网络中有3 台打印机需要使用池中保留的静态IP 地址。

池中有多少IP 地址分配给其他主机?如果分配给池的地址块是192.168.10.0/24,则网络上的主机可分配到254 个IP 地址。

由于有3 台打印机需要静态分配地址,则剩余251 个IP 地址可供分配。

最新CCNA第一学期第八章答案7、下列哪种网络迁移技术可以把IPv6 数据包封装在IPv4 数据包中,以便通过IPv4 网络基础架构进行传输?隧道迁移技术可将IPv6 数据包封装在IPv4 数据包中。

封装过程中会组装消息并向每一层添加信息,以便通过网络传输数据。

转换迁移技术允许支持IPv6 的设备与支持IPv4 的设备使用类似于IPv4 中NAT 的转换技术进行通信。

双堆栈迁移技术允许IPv4 和IPv6 协议栈在同一网络中同时共存。

CCNA第一学期各章习题和参考答案.doc

CCNA第一学期各章习题和参考答案.doc

CCNA第一学期各章习题和参考答案第二章网络通信1、TCP/IP网络接入层有何作用?A路径确定和数据包交换B数据表示、编码和控制C可靠性、流量控制和错误检测E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)B发起数据通信D发送数据流F数据流最后的终止点3、下列哪三项陈述是对局域网(LAN) 最准确的描述?(选择三项)C LAN 中的不同网段之间一般通过租用连接的方式连接。

D此类网络的安全和访问控制由服务提供商控制。

F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?A传输期间的帧损坏B在目的设备上重组的数据C因通信丢失而重新传输的数据包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)018哪个应用层协议通常用于支持客户端与服务器之间的文件传输?A HTMLB HTTP D Telnet019哪个应用层协议中规定了Microsoft 网络中用于文件共享的服务?A DHCPB DNS D SMTP E Telnet020服务器上的应用层通常如何处理多客户端服务请求?A终止与服务的所有连接B拒绝与单一守护程序的多个连接C暂停当前连接,建立新连接第四章OSI传输层001下列哪两项是用户数据报协议(UDP) 的功能?(选择两项)A流量控制 D 面向连接E 序列和确认002请参见图示。

此Wireshark 捕获输出的第7 行中执行的是哪一项TCP 操作?A会话创建B 数据段重传C 数据传输D 会话断开003数据段的TCP 报头中为什么包含端口号?A指示转发数据段时应使用的正确路由器接口B 标识接收或转发数据段时应使用的交换机端口C确定封装数据时应使用的第3 层协议让接收主机转发数据到适当的应用程序E让接收主机以正确的顺序组装数据包004OSI 模型哪一层负责规范信息从源设备到目的设备准确可靠地流动?A应用层 B 表示层 C 会话层传输层 E 网络层005请参见图示。

CCNA第一学期各章知识题及答案解析

CCNA第一学期各章知识题及答案解析

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002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006请参见图示。

所示网络属于哪一类型?WANMANLANWLAN007 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009 请参见图示。

ccna 章节与期末答案

ccna 章节与期末答案

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。

ccna考试题及答案

ccna考试题及答案

ccna考试题及答案1. 以下哪项是网络层的功能?A. 路由选择B. 错误检测C. 流量控制D. 封装数据包答案:A2. 在OSI模型中,哪一层负责在网络中传输数据?A. 应用层B. 传输层C. 会话层D. 网络层答案:D3. 以下哪个协议是用于在IP网络中发现网络设备的?A. ARPB. RARPC. ICMPD. OSPF答案:A4. 在TCP/IP模型中,哪一层与OSI模型的传输层相对应?A. 应用层B. 互联网层C. 网络接口层D. 传输层答案:D5. 以下哪个地址是一个有效的IPv4地址?A. 192.168.1.256B. 192.168.1.1C. 10.0.0.0D. 172.16.300.1答案:B6. 在配置路由器时,以下哪个命令用于进入全局配置模式?A. enableB. configure terminalC. privileged execD. user exec答案:B7. 以下哪个命令用于在Cisco设备上显示当前配置?A. show running-configB. show startup-configC. show configD. show current-config答案:A8. 在Cisco设备上,以下哪个命令用于保存当前的配置到启动配置文件?A. copy running-config startup-configB. copy startup-config running-configC. save running-configD. save startup-config答案:A9. 以下哪个命令用于在Cisco设备上查看所有接口的状态?A. show interfacesB. show ip interface briefC. show interface statusD. show running-config interface答案:B10. 在Cisco设备上,以下哪个命令用于关闭接口?A. shutdownB. no shutdownC. disableD. no enable答案:A11. 以下哪个命令用于在Cisco设备上启用接口?A. shutdownB. no shutdownC. disableD. no enable答案:B12. 在配置静态路由时,以下哪个命令用于指定下一跳地址?B. ip static-routeC. route ipD. static-route ip答案:A13. 以下哪个命令用于在Cisco设备上清除ARP表?A. clear arp-cacheB. clear arpC. clear arp tableD. clear ip arp答案:D14. 在配置动态路由协议时,以下哪个命令用于在接口上启用RIP?A. ip rip enableB. ip rip receiveD. network rip答案:C15. 以下哪个命令用于在Cisco设备上查看RIP路由表?A. show ip ripB. show ip route ripC. show ripD. show ip protocols答案:B16. 在配置EIGRP时,以下哪个命令用于指定自动汇总?A. metric weightsB. auto-summaryC. network auto-summaryD. no auto-summary答案:B17. 以下哪个命令用于在Cisco设备上查看EIGRP邻居?A. show ip eigrp neighborsB. show eigrp neighborsC. show ip eigrpD. show eigrp interfaces答案:A18. 在配置OSPF时,以下哪个命令用于指定路由器ID?A. router-idB. router ospfC. networkD. area答案:A19. 以下哪个命令用于在Cisco设备上查看OSPF路由表?A. show ip ospfB. show ip ospf databaseC. show ospfD. show ip route ospf答案:D20. 在配置VLAN时,以下哪个命令用于创建一个新的VLAN?A. vlan databaseB. configure terminalC. vlan [vlan-id]D. new-vlan答案:C21. 以下哪个命令用于将接口分配给VLAN?A. switchport mode accessB. switchport mode trunkC. switchport access vlan [vlan-id]D. switchport trunk vlan [vlan-id]答案:C22. 在配置交换机时,以下哪个命令用于将接口设置为Trunk 模式?A. switchport mode accessB. switchport mode trunkC. switchport access vlan [vlan-id]D. switchport trunk vlan [vlan-id]答案:B23. 以下哪个命令用于在Cisco设备上查看VLAN配置?A. show vlanB. show vlan briefC. show vlan detailD. show vlan all答案:B24. 在配置VTP时,以下哪个命令用于将交换机设置为VTP服务器模式?A. vtp mode serverB. vtp mode clientC. vtp mode transparentD. vtp mode off答案:A25. 以下哪个命令用于在Cisco设备上查看VTP状态?A. show vtp statusB. show vtp statisticsC. show vtp passwordD. show vtp configuration答案:A26. 在配置STP时,以下哪个命令用于设置根桥?A. spanning-tree root primaryB. spanning-tree root secondaryC. spanning-tree root primary [priority]D. spanning-tree root secondary [priority]答案:C27. 以下哪个命令用于在Cisco设备上查看STP状态?A. show spanning-treeB. show spanning-tree detailC. show spanning-tree summaryD. show spanning-tree interface答案:A28. 在配置VLAN Trunking Protocol (VTP) 时,以下哪个命令用于设置VTP域名?A. vtp domain [domain-name]B. vtp password [password]C. vtp mode [mode]D. vtp version [version]答案:A29. 以下哪个命令用于在Cisco设备上查看当前的VTP版本?A. show vtp statusB. show vtp statisticsC. show vtp passwordD. show vtp configuration答案:A30. 在配置端口安全时,以下哪个命令用于限制接口上可以学习到的最大MAC地址数量?A. switchport port-security maximum [mac-count]B. port-security maximum [mac-count]C. switchport port-security violation restrictD. port-security violation shutdown答案:A这些题目和答案仅供学习和参考之用,实际的CCNA考试内容和形式可能会有所不同。

CCNA考试题库中英文翻译版及答案

CCNA考试题库中英文翻译版及答案

CCNA考试题库中英⽂翻译版及答案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,⽹络管理员会使⽤访问列表?A、 to control vty access into a routerA、控制通过VTY访问路由器B、 to control broadcast traffic through a routerB、控制⼴播流量穿越路由器2、⼀个默认得帧中继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得中央,当⼤多数⽤户在⼤流量传输数⼀些⽆线⽤户发现⽆线⽹络变得缓慢与出现丢包A、 mismatched TKIP encryptionB、 null SSIDC、 cordless phonesD、 mismatched SSIDE、 metalF、 antenna type or directionAnswer: CEF4、 Refer to the exhibit、 How many broadcast domains exist in the exhibited topology?根据下图,图中得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得overlap得区域描述了⼀个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中得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得频道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、路由器上输⼊命令frame-relay map ip 10、121、16、8 102 broadcast,以下选项正确得就是?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就是本地路由器⽤来转发数据得接⼝C、 102 is the remote DLCI that will receive the information、C、102就是远端得DLCI它将接受信息。

CCNA认证试题(中文+答案)

CCNA认证试题(中文+答案)

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。

最新CCNA认证试题及答案「中文版」

最新CCNA认证试题及答案「中文版」

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。

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最新CCNA第一学期第八章答案
IPv4 地址分为两个部分:网络部分- 用于识别主机所在的特定网络,主机部分- 用于识别网络中的特定主机。

子网掩码用于识别各个部分的长度。

255.255.255.224 的二进制格式为11111111.11111111.11111111.11100000。

前缀长度是指子网掩码中连续的 1 的个数。

因此,前缀长度为/27。

定向广播是将消息发送到特定网络中的所有主机。

它适用于将广播发送到非本地网络中的所有主机。

组播消息是将消息发送到订阅组播组中的一组选定主机。

有限广播只限于将消息发送到本地网络中的主机。

单播消息是将消息从一台主机发送到另一台主机。

许多协议使用广播,因此无法避免。

路由器不转发广播,因此会在其每个接口形成一个广播域。

IPv6 中没有广播。

如果交换机收到广播数据包,它将通过除入站接口以外的所有接口转发此数据包。

6、DHCP 服务器用于为网络上的主机动态分配IP 地址。

地址池配置为192.168.10.0/24。

该网络中有 3 台打印机需要使用池中保留的静态IP 地址。

池中有多少IP 地址分配给其他主机?
如果分配给池的地址块是192.168.10.0/24,则网络上的主机可分配到254 个IP 地址。

由于有 3 台打印机需要静态分配地址,则剩余251 个IP 地址可供分配。

7、下列哪种网络迁移技术可以把IPv6 数据包封装在IPv4 数据包中,以便通过IPv4 网络基础架构进行传输?
隧道迁移技术可将IPv6 数据包封装在IPv4 数据包中。

封装过程中会组装消息并向每一层添加信息,以便通过网络传输数据。

转换迁移技术允许支持IPv6 的设备与支持IPv4 的设备使用类似于IPv4 中NAT 的转换技术进行通信。

双堆栈迁移技术允许IPv4 和IPv6 协议栈在同一网络中同时共存。

组播、任播和单播属于IPv6 地址类型。

IPv6 中没有广播地址。

环回和本地链路是单播地址的特定类型。

IPv6 全局单播地址包括三个要素。

由ISP 提供的全局路由前缀,由组织确定的子网ID,以及唯一标识主机接口的接口ID。

12、支持IPv6 的设备发送一个目的地址为FF02::1 的数据包。

该数据包的目标是什么?
FF02::1 是本地链路范围内的全节点组播组。

所有支持IPv6 的接口将接收和处理具有此目的地址的数据包。

13、当思科路由器从IPv4 环境完全迁移到IPv6 环境时,哪组命令可以正确启用IPv6 转发和接口寻址?
ICMPv4 和ICMPv6 通用的ICMP 消息包括:主机确认、目标(网络、主机、协议、端口)或服务不可达、超时和路由重定向。

路由器请求、邻居请求和路由器通告是ICMPv6 中实施的新协议。

15、当支持IPv6 的主机需要发现预期IPv6 目标的MAC 地址时,源主机将在NS 消息中使用下列哪个目的地址?
当主机需要查找目的主机的MAC 地址时,则使用地址解析。

IPv6 主机设备将发送邻居请求(NS) 消息到请求节点组播地址。

此地址包括两个部分,共同构成了128 位的地址。

前半部分是FF02::1:FF00/104,
后半部分是目的主机的本地链路地址或全球单播地址的最右边24 位。

当路由器收到一个traceroute 数据包时,TTL 字段的值递减1。

当该字段中的值达到零时,接收路由器不会转发数据包,并会向源发送ICMP 超时消息。

IPv6 地址::1 是环回地址。

对该地址成功执行ping 操作意味着TCP/IP 协议栈已正确安装。

但并不意味着所有地址配置正确。

要确定给定的IPv4 地址是网络地址、主机地址还是广播地址,首先应当根据子网掩码确定地址空间。

将地址和掩码转换为二进制值,并使用AND 运算确定网络地址。

要计算地址空间,则使用子网掩码中的主
机位数,指数为2。

空间中的有效主机地址数量是该数字减2。

网络地址的主机部分全部为0,而广播地址全部为1。

例如,10.0.50.10/30 可以产生网络IP 地址10.0.50.8,掩码使用给定的地址进行AND 运算。

由于掩码只有 2 个主机位,因此只有 2 个有效主机地址(4 - 2)。

10.0.50.10 是两个有效主机IP 地址之一。

您可以写出的8 位字节最大数字是11111111,该值可以转换为十进制255。

A 类地址的范围从0.0.0.0/8 到127.0.0.0/8。

B 类地址的范围从128.0.0.0/16 到191.255.0.0/16。

C 类地址的范围从192.0.0.0/24 到223.255.255.0/24。

D 类地址的范围从224.0.0.0 到239.255.255.255。

242.56.6.1 属于E 类地址范围。

本地链路地址由操作系统环境自动分配,并且位于地址块169.254.0.0/16 中。

私有地址范围是10.0.0.0/8、172.16.0.0/12 和192.168.0.0/16。

TEST-NET 地址属于范围192.0.2.0/24。

地址块240.0.0.0 到255.255.255.254 中的地址留作实验地址。

环回地址属于地址块127.0.0.0/8。

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