计算机网络习题.doc

问题 1得 0 分，满分 10 分 Which of the following OSPF commands, when used together, will put the network /24 into OSPF area 0? (Select all valid responses)所选答案： A. Router(config-router)# network 55 area 0 正确答案： A. Router(config-router)# network 55 area 0 D. Router(config)# router ospf 1 反馈：The network command specifies the IP address () followed by the wildcard mask (not the subnet mask), and the area that is to be associated with the OSPF address range (in this case, area 0). The wildcard mask indicates in binary how much of the IP address much be matched with 0s indicating that the bits must match and 1 indicating that they may vary. Thus 55 or 00000000.00000000.00000000.11111111 indicates that any bit in the last octet can vary while all bits in the first 3 octets must match the network address (in other words,192.168.10.xx) 问题 2得 0 分，满分 10 分 On the topic of the OSPF hello protocol; which of the statements below are true? (Select two answer choices)所选答案： A. The OSPF Hello protocol provides dynamic neighbor discovery 正确答案： A. The OSPF Hello protocol provides dynamic neighbor discovery C. The OSPF Hello protocol maintains neighbor relationships 反馈：OSPF contains a protocol (the Hello protocol) that is used to establish and maintain relationships between neighboring nodes. These relationships are called adjacencies. Adjacencies are the basis for the exchange of routing data in OSPF. 问题 3得 0 分，满分 10 分 Which of the following technologies can be used in distance vector routing protocols to prevent routing loops? (Select all valid answer choices)所选答案： A. Shortest path first tree 正确答案： C. Hold-down timers D. Split horizon 反馈：Distance vector routing protocols use the rule of split horizons and hold down timers to prevent routing loops after a topology change.*Splithorizon -the routing protocol advertises routes out an interface only if they were not learned from updates ententering that interface. * Hold-down timer - After finding out that a router to a subnet has failed, a router waits acertain period of time before believing any other routing information about that subnet. 问题 4得 0 分，满分 10 分 A TestKing Switch is connected as shown below: Which IOS commands should you enter if you wanted to link the router TestKing1 with switch port 1? (Select three answer choices) 234.GIF所选答案： A. Switch(config)# interface fastethernet 0/1 正确答案： A. Switch(config)# interface fastethernet 0/1 C. Switch(config-if)# switchport mode trunk D. Switch(config-if)# switchport trunk encapsulation dot1q 反馈：Before you can begin, you have to get into the interface. Answer choice A is the only command in the selection that puts the IOS into interface mode. Once in the interface you have to set it to trunk mode, so choice C is correct. 问题 5得 0 分，满分 10 分 Which interface commands would you enter on a Catalyst 2900 switch, if your goal was to bring all VLAN traffic to another directly connected switch? (Select the two valid responses)所选答案： A. Switch(config-if)# vlan all 正确答案： C. Switch(config-if)# switchport access vlan all D. Switch(config-if)# switchport mode trunk 反馈：In order to pass all VLAN traffic from one switch to another, a trunk is needed. In order to configure a trunk on a 2900 series switch, only these two commands are required. 问题 6得 0 分，满分 10 分 What are the characteristic of link state routing protocols? (Choose all that apply.)所选答案： A. The exchange of advertisement is triggered by a change in the network 正确答案： A. The exchange of advertisement is triggered by a change in the network C. Packets are routed based upon the shortest path to the destination D. Every router in an OSPF area is capable of representing the entire network topology 问题 7得 0 分，满分 10 分 Which of the following routing protocols are less likely prone routing loops and network reachability problems when used in discontiguous networks? (Select all valid responses)所选答案： A. OSPF 正确答案： A. OSPF D. EIGRP 反馈：Only OSPF, RIP version 2, and EIGRP carry VLSM information. In a discontiguous network, subnet masks of different lengths can be used, but this information will need to be propagated via the routing protocol if all networks are to be reached. 问题 8得 0 分，满分 10 分 A Catalyst 2950 needs to be reconfigured. What steps will ensure that the old configuration is erased? (Choose three)所选答案： A. Modify the configuration register 正确答案： B. Restart the switch C. Delete the VLAN database D. Erase the startup configuration 反馈：For switches such as the 2950, the process is much the same as a router, but you should delete the VLAN.DAT file before reloading the router. This file contains VLAN information and is kept in flash, so it will still be present after a reload. 问题 9得 0 分，满分 10 分 An administrator would like to configure a switch over a virtual terminal connection from locations outside of the local LAN. Which of the following are required in order for the switch to be configured from a remote location? (Choose two)所选答案： A. The switch must be reachable through a port connected to its management VLAN 正确答案： A. The switch must be reachable through a port connected to its management VLAN D. The switch must be configured with an IP address, subnet mask, and default gateway 反馈：In order the telnet to any Cisco device, the device must be reachable from the remote location. For a Cisco switch to be reachable from remote locations, it must have an IP address, subnet mask, and default gateway assigned. Communication with the switch . 问题 10得 0 分，满分 10 分 Which of the following describe private IP addresses? (Choose two)所选答案： A. Addresses chosen by a company to communicate with the Internet. 正确答案： B. Addresses that cannot be routed through the public Internet. D. A scheme to conserve public addresses. 反馈：Private IP address space has been allocated via RFC 1918. This means the addresses are available for any use by anyone and therefore the same private IP addresses can be reused. However they are defined as not routable on the public Internet. 问题 11得 0 分，满分 10 分 Two TestKing routers are connected together as shown in the diagram below: You work as a network administrator at TestK. You attempt to telnet from the console port on Router TestKing1 to 5. The Telnet connection is unsuccessful. However, a ping to 5 is successful.What could cause this problem? (Select two) 237.GIF所选答案： A. access control list filtering 正确答案： A. access control list filtering D. missing VTY password 反馈：Since a ping to 5 is successful we can eliminate IP configuration being incorrect,however a telnet session is not successful could indeed be because the vty password is not set or missing.To be able to telnet to the router you need the set the telnet with line vty 0 4 command.Also, C is correct because an access list that was placed on the router could be configured to deny the telnet traffic, while at the same time permitting ICMP ping traffic. 问题 12得 0 分，满分 10 分 In EIGRP, what kind of route information is stored in the RAM of the router and main-tained by way of hello packets and update packets? (Select two answer choices)所选答案： A. Neighbor Table 正确答案： A. Neighbor Table D. Topology Table 反馈：In EIGRP the only two tables of significance are the neighbor table and the topology table. 问题 13得 0 分，满分 10 分 The TestKing switches shown in the diagram, Core and Core2, are both Catalyst 2950s. The addressing scheme for each company site is as follows: Router Ethernet port - 1st usable address Core - 2nd usable address Core2 - 3rd usable address For this network, which of the following commands must be configured on Core2 to allow it to be managed remotely from any subnet on the network? (Choose three) 236.GIF所选答案： A. Core2(config)# ip default-gateway 正确答案： A. Core2(config)# ip default-gateway B. Core2(config)# interface vlan 1 Core2(config-if)# ip address 1 48 C. Core2(config)# line vty 0 4 Core2(config-line)# password cisco 反馈：IP default-gateway address is a global command that sets the default gateway so that themanagement interface can be reached from a remote network. This is the correctcommand used on Cisco switches. In order to be reachable, the IP address of VLAN 1must also be specified and must be in the same subnet as the default gateway IP address.Finally, in order to remotely connect via telnet to any Cisco device the password must eset or you will get a password required, but none set error message when you try to telnet to it. 问题 14得 0 分，满分 10 分 Which of the following OSPF commands, when used together, will put the network /24 into OSPF area 0? (Select all valid responses)所选答案： A. Router(config-router)# network 55 area 0 正确答案： A. Router(config-router)# network 55 area 0 D. Router(config)# router ospf 1 反馈：The network command specifies the IP address () followed by the wildcard mask (not the subnet mask), and the area that is to be associated with the OSPF address range (in this case, area 0). The wildcard mask indicates in binary how much ofthe IP address much be matched with 0s indicating that the bits must match and 1indicating that they may vary. Thus 55 or00000000.00000000.00000000.11111111 indicates that any bit in