1、思科认证 640-802-试卷 1 及答案解析(总分：16.00，做题时间：90 分钟)一、单选题(总题数：7，分数：14.00)1.When you use the ping command to send ICMP messages across a network, whats the most common request/reply pair youll see? (Select one answer choice)（分数：2.00）A.Echo request and Echo replyB.ICMP hold and ICMP sendC.ICMP request and ICM
2、P replyD.Echo off and Echo onE.None of the above2.You need to perform some initial configuration tasks on a new Ezonexam switch. What is the purpose of assigning an IP address to a switch?（分数：2.00）A.To provide local hosts with a default gateway addressB.To allow remote management of the switch.C.To
3、allow the switch to respond to ARP requests between two hostsD.To ensure that hosts on the same LAN can communicate with each other.E.None of the above3.Which VTP mode should a Cisco switch be set to if this switch is to add or delete VLANs to a management domain?（分数：2.00）A.TransparentB.ServerC.Auto
4、D.ClientE.User4.Your network uses the172.12.0.0 class B address. You need to support 459 hosts per subnet, while accommodating the maximum number of subnets. Which mask would you use?（分数：2.00）A.255.255.0.0.B.255.255.128.0.C.255.255.224.0.D.255.255.254.0.E.None of the above5.You download a file from
5、an FTP site on the Internet. What is the highest layer in the OSI model used in this FTP operation?A. ApplicationB. PresentationC. SessionD. TransportE. InternetF. Data LinkG. Physical（分数：2.00）填空项 1:_6.The Ezonexam network administrator needs to verify that switch interface 0/5 has been assigned to
6、the Marketing VLA.N. Which command will accomplish this task?A. Show vlanB. Show mac-address-tableC. Show vtp statusD. show spanning-tree rootE. show ip interface briefF. None of the above（分数：2.00）填空项 1:_7.You have a network that supports VLSM and you need to reduce IP address waste in your point to
7、 point WAN links. Which of the masks below would you use?A. /38B. /30C. /27D. /23E. /18F. /32（分数：2.00）填空项 1:_二、多选题(总题数：1，分数：2.00)8.The Ezonexam network administrator issues the ping 192.168.2.5 command and successfully tests connectivity to a host that has been newly connected to the network. Which
8、protocols were used during the test? (Choose two)（分数：2.00）A.ARPB.CDPC.DHCPD.DNSE.ICMP思科认证 640-802-试卷 1 答案解析(总分：16.00，做题时间：90 分钟)一、单选题(总题数：7，分数：14.00)1.When you use the ping command to send ICMP messages across a network, whats the most common request/reply pair youll see? (Select one answer choice)（
9、分数：2.00）A.Echo request and Echo reply B.ICMP hold and ICMP sendC.ICMP request and ICMP replyD.Echo off and Echo onE.None of the above解析：解析：Explanation: The ICMP protocol uses Echo request and Echo reply with the Ping command. The PING utility is the most commonly used message to verify connectivity
10、to a remote device within the network.2.You need to perform some initial configuration tasks on a new Ezonexam switch. What is the purpose of assigning an IP address to a switch?（分数：2.00）A.To provide local hosts with a default gateway addressB.To allow remote management of the switch. C.To allow the
11、 switch to respond to ARP requests between two hostsD.To ensure that hosts on the same LAN can communicate with each other.E.None of the above解析：解析：Explanation: Switch is a layer 2 device and doesnt use network layer for packet forwarding. The IP address may be used only for administrative purposes
12、such as Telnet access or for network management purposes.3.Which VTP mode should a Cisco switch be set to if this switch is to add or delete VLANs to a management domain?（分数：2.00）A.TransparentB.Server C.AutoD.ClientE.User解析：解析：Explanation: VTP Modes: If you intend to make a switch part of a VTP mana
13、gement domain, each switch must be configured in one of three possible VTP modes. The VTP mode assigned to a switch will determine how the switch interacts with other VTP switches in the management domain. The three VTP modes that can be assigned to a Cisco switch include server mode, client mode, a
14、nd transparent mode. Each of these roles is outlined below: Server Mode: Once VTP is configured on a Cisco switch, the default mode used is Server Mode. In any given VTP management domain, at least one switch must be in Server Mode. When in Server Mode, a switch can be used to add, delete, and modif
15、y VLANs, and this information will be passed to all other switches in the VTP management domain. Client Mode: When a switch is configured to use VTP Client Mode, it is simply the recipient of any VLANs added, deleted, or modified by a switch in Server Mode within the same management domain. A switch
16、 in VTP client mode cannot make any changes to VLAN information. Transparent Mode: A switch in VTP Transparent Mode will pass VTP updates received by switches in Server Mode to other switches in the VTP management domain, but will not actually process the contents of these messages. When individual
17、VLANs are added, deleted, or modified on a switch running in transparent mode, the changes are local to that particular switch only, and are not passed to other switches in the VTP management domain. Based on the roles of each VTP mode, the use of each should be more or less obvious. For example, if
18、 you had 15 Cisco switches on your network, you could configure each of them to be in the same VTP management domain. Although each could theoretically be left in the default Server Mode, it would probably be easier to leave only one switch in this configuration, and then configure all remaining swi
19、tches for VTP Client Mode. Then, when you need to add, delete, or modify a VLAN, that change can be carried out on the VTP Server Mode switch and passed to all Client Mode switches automatically. In cases where you need a switch to act in a relatively standalone manner, or do not want it to propagat
20、e information about its configured VLANs, use Transparent Mode. Incorrect Answers: A. A switch in VTP Transparent Mode will pass VTP updates received by switches in Server Mode to other switches in the VTP management domain, but will not actually process the contents of these messages. C, E. These a
21、re not valid VTP modes. D. Client mode merely accepts changes made by the switch that is connected and in SERVER mode.4.Your network uses the172.12.0.0 class B address. You need to support 459 hosts per subnet, while accommodating the maximum number of subnets. Which mask would you use?（分数：2.00）A.25
22、5.255.0.0.B.255.255.128.0.C.255.255.224.0.D.255.255.254.0. E.None of the above解析：解析：Explanation: To obtain 459 hosts the number of host bits will be 9. This can support a maximum of 510 hosts. To keep 9 bits for hosts means the last bit in the 3rd octet will be 0. This gives 255.255.254.0 as the sub
23、net mask.5.You download a file from an FTP site on the Internet. What is the highest layer in the OSI model used in this FTP operation?A. ApplicationB. PresentationC. SessionD. TransportE. InternetF. Data LinkG. Physical（分数：2.00）填空项 1:_ （正确答案：正确答案：A）解析：解析：Explanation: Layer 7 is the application laye
24、r, which is the highest layer in the OSI model. This layer describes the use of end user applications, such as opening movie files (avi, mpeg, etc) used Microsoft Office applications, using WWW browsers, using Telnet, and using FTP.6.The Ezonexam network administrator needs to verify that switch int
25、erface 0/5 has been assigned to the Marketing VLA.N. Which command will accomplish this task?A. Show vlanB. Show mac-address-tableC. Show vtp statusD. show spanning-tree rootE. show ip interface briefF. None of the above（分数：2.00）填空项 1:_ （正确答案：正确答案：A）解析：解析：Explanation: The “show vlan“ command display
26、s the configured vlan name and ID as well as the ports that belong to each VLAN, etc. By default all ports belongs to VLAN 1 Note: You can also use: show vlan brief, show vlan ID where ID is the VLAN ID.7.You have a network that supports VLSM and you need to reduce IP address waste in your point to
27、point WAN links. Which of the masks below would you use?A. /38B. /30C. /27D. /23E. /18F. /32（分数：2.00）填空项 1:_ （正确答案：正确答案：B）解析：解析：Explanation: For a single point to point link, only 2 IP addresses are required, one for the serial interface of the router at each end. Therefore, the 255.255.255.252 subn
28、et mask is often used for these types of links because no IP addresses are wasted. The subnet mask 255.255.255.252 is a /30, so answer B is correct. Incorrect Answers: A. The largest mask that can be used is the single IP host mask, which is /32. It is not possible to use a /38 mask, unless of cours
29、e IPv6 is being used. C, D, E. These masks will provide for a larger number of host addresses, and since only 2 IP addresses are needed for a point to point link, these extra addresses are wasted. F: No available host addresses with a /32 mask二、多选题(总题数：1，分数：2.00)8.The Ezonexam network administrator
30、issues the ping 192.168.2.5 command and successfully tests connectivity to a host that has been newly connected to the network. Which protocols were used during the test? (Choose two)（分数：2.00）A.ARP B.CDPC.DHCPD.DNSE.ICMP 解析：解析：Explanation: ARP finds the hardware address of a host from a known IP add
31、ress. Heres how it works: when IP has a datagram to send, it must inform a Network Access protocol, such as Ethernet or Token Ring, of the destinations hardware address on the local network. (It has already been informed by upper-layer protocols of the destinations IP address.) If IP doesnt find the
32、 destination hosts hardware address in the ARP cache, it uses ARP to find this information. ICMP works at the Network layer and is used by IP for many different services. ICMP is a management protocol and messaging service provider for IP. Its messages are carried as IP datagrams. RFC 1256 is an ann
33、ex to ICMP, which affords hosts extended capability in discovering routes to gateways. Periodically, router advertisements are announced over the network, reporting IP addresses for the routers network interfaces. Hosts listen for these network infomercials to acquire route information. A router solicitation is a request for immediate advertisements and may be sent by a host when it starts up.
