CCNA第二学期练习题七.doc

1 请参见图示。如果所有路由器都运行RIP第2版，为什么没有192.168.1.32/27网络的路由？ Refer to the exhibit. If all routers are running RIP version 2, why is there no route for the 192.168.1.32/27 network? 3 Rip第2版不会在更新中发送子网掩码。 Rip version 2 does not send subnet masks in its updates. 路由器A并未将RIP设置为路由协议。 Router A is not setup with RIP as a routing protocol. Rip第2版默认将自动总结路由。 Rip version 2 will auto summarize routes by default. 路由器B未设置为通告192.168.1.64/30网络。Router B is not setup to advertise the 192.168.1.64/30 network. 2 请参见图示。下列哪个路由器上的哪条命令可让Router1获知192.168.0.0/20网络？3 Refer to the exhibit. Which command on which router will allow Router1 to learn about the 192.168.0.0/20 network? Router1(config)# ip classless Router1(config-router)# no passive-interface serial 0/1/1 Router2(config-router)# version 2 Router2(config-router)# neighbor 10.0.0.2 3、哪两项是选择实施RIP第2版而不是RIP第1版的原因？（选择两项。）14 What are two reasons to implement RIP version 2 rather than RIP version 1? RIP第2版支持VLSM。 RIP第2版支持16台以上的路由器。 RIP第2版支持有类（而不是无类）路由 RIP第2版支持路由更新验证。 RIP第2版支持多区域。 RIP第2版使用Dijkstra算法而不是贝尔曼-福特算法。4、RIP v1和RIP v2的相似点有哪些？（选择三项。）126 How are RIP v1 and RIP v2 similar to one another? 两者都使用跳数作为度量。 They both use hop count as a metric. 两者对无穷距离使用相同的度量值。 They both have the same metric value for infinite distance. 两者都向邻居广播其更新。 They both use a broadcast IP address to send updates to their neighbors. 两者都在更新中发送子网掩码信息。 They both send subnet mask information in their updates. 两者都对更新来源进行身份验证。 They both provide for authentication of update sources. 两者都使用水平分割来防止路由环路。 They both use split horizon to prevent routing loops. 5 请参见图示。路由器East和West被配置为使用RIPv1。两台路由器都会发送有关其直连路由的更新。East路由器可以ping通West路由器的串行接口，West可以ping通East的串行接口。但是，两台路由器都无法从对方动态获知路由。最可能的原因是什么？3 Refer to the exhibit. Routers East and West are configured using RIPv1. Both routers are sending updates about their directly connected routes. The East router can ping the West router serial interface and West can ping the serial interface of East. However, neither router has dynamically learned routes from the other. What is most likely the problem? 需要配置最后选用网关。 A gateway of last resort is required. 子网划分不受RIPv1支持。 Subnetting is not supported by RIPv1. VLSM不受RIPv1支持。 VLSM is not supported by RIPv1. 其中一台路由器的串行接口需要时钟频率。One of the routers needs a clock rate on the serial interface. 6 请参见图示。下列哪条命令可让Router2获知192.168.16.0/28网络？2 Refer to the exhibit. Which command will allow Router2 to learn about the 192.168.16.0/28 network? Router1(config)# ip classless Router1(config-router)# network 192.168.16.0 Router1(config-router)# no passive-interface serial 0/1/1 Router2(config-router)# version 2 Router2(config-router)# neighbor 10.0.0.2 7 请参见图示。所有路由器都运行RIP第2版。JAX被配置为仅通告10.0.0.0/24网络。CHI被配置为通告172.16.0.0/16网络。网络管理员输入如图所示的命令。该网络中将会发生什么变化？2 Refer to the exhibit. All routers are running RIP version 2. JAX is configured to just advertise the 10.0.0.0/24 network. CHI is configured to advertise the 172.16.0.0/16 network. A network administrator enters the commands shown in the exhibit. What changes will occur in this network? 由于水平分割的原因，JAX路由器将忽略172.16.0.0/16网络的更新。 The JAX router will ignore updates for the 172.16.0.0/16 network due to split horizon issues. CHI将在其路由表中安装到192.168.0.0/16网络的路由。 The CHI router will install a route to the 192.168.0.0/16 network in its routing table. CHI的路由表中将包含192.168.0.0/16路由，但该路由旁边将标记S。 The routing table for CHI will have the 192.168.0.0/16 route but it will have an S next to the route. ORL路由器将对其路由更新中转发的所有网络应用255.255.0.0子网掩码。 The ORL router will apply a 255.255.0.0 subnet mask to all networks in the routing updates it forwards.8 请参见图示。技术人员需要添加一个新的环回接口以便测试路由运作情况和网络设计。该技术人员在路由器上输入下列一组命令：Refer to the exhibit. A technician needs to add a new loopback interface to test routing functionality and network design. The technician enters the following set of commands on the router:Sanford(config)# interface loopback1Sanford(config-if)# ip address 192.168.6.62 255.255.255.252为什么该路由器返回错误？4 Why does the router respond with an error?该路由器不允许环回接口配置。 The router does not allow loopback interface configurations. 该掩码不能用于这个地址类。 This mask can not be used with this class of addresses. 在添加这个地址之前必须配置无类路由。 Classless routing must be configured before this address can be added. Loopback1的网络地址与之前配置的接口地址重叠。 The network address for Loopback1 overlaps with an already configured interface address. 该路由器已经超出其路由表所能提供的最大路径数限制。 The router is over the limit for the maximum paths that can be provided in the routing table.9、RIPv2的默认度量允许的最大网络直径为多少？1 What is the maximum network diameter permitted by the default metric of RIPv2? 15跳 16跳 100跳 120跳 255跳 10、配置路由协议时使用network命令有哪两项作用？（选择两项。）15 What are two functions of the network command used when configuring routing protocols? 标识将包含在路由更新中的网络 identifies which networks will be included in the routing updates 标识网络中可以进行总结的主机地址 identifies the hosts addresses that can be summarized in the network 用于列出远程和本地网络的所有地址 used to list all addresses for remote and local networks 确定要对路由更新应用的子网掩码 determines which subnet mask to apply to routing updates 确定哪些接口可以发送和接收路由更新 determines which interfaces can send and receive routing updates11 请参见图示。从如图所示的输出中能得到什么结论？4Refer to the exhibit. What can be concluded from the output shown in the exhibit? 路由表被限制为只能有2条路由。The routing table is limited to 2 routes.LAN接口参与了路由过程。The LAN interfaces are participating in the routing process 已经从每个串行接口各发出一个更新并已收到2个更新。One update has been sent out of each serial interface and 2 have been received. 此路由器上未配置no auto-summary。 The no auto-summary has not been configured on this router.12、网络管理员被告知公司的IP地址基础架构必须符合RFC 1918。管理员可以在该网络中使用RFC 1918规定的哪三个IP地址范围？（选择三项。）145 A network administrator has been told that the company IP address infrastructure must adhere to RFC 1918. What three IP address ranges from RFC 1918 could the administrator use on the network? 10.0.0.0/8 127.0.0.0/8 169.254.0.0/16 172.16.0.0/12 192.168.0.0/16 209.165.201.0/27 13 请参见图示。所有路由器都运行RIPv1。如果在路由器B上配置了地址为10.16.1.129/27的环回接口，那么路由器B的路由表将发生什么变化？2 Refer to the exhibit. All routers are running RIPv1. What changes will occur in the routing table of router B if a loopback interface with an address of 10.16.1.129/27 is configured on router B? 将添加到10.16.1.0/27、10.16.1.64/27和10.16.1.128/27网络的路由。Routes to the 10.16.1.0/27, 10.16.1.64/27, and 10.16.1.128/27 networks are added. 将添加到10.16.1.128/27网络的相连路由。 A connected route to the 10.16.1.128/27 network is added. 将添加来源为RIPv1的第三条到10.0.0.0/8网络的路由。 A third route to the 10.0.0.0/8 network with RIPv1 as the source is added. 配置路由器B之后，路由表将立即删除10.0.0.0/8路由。 The 10.0.0.0/8 route is dropped immediately from the routing table after router B is configured.14、网络管理员安装了四台运行RIPv2的新路由器。Router1是RIPv2网络中的边界路由器，其上配置了默认路由。当网络收敛后，网络管理员在Router1上输入Router1(config-router)# default-information originate。该命令将对网络产生什么影响？4 A network administrator installed four new routers that are running RIPv2. Router1 is a boundary router in the RIPv2 network and has a default route configured. Once the network has converged, the network administrator enters Router1(config-router)# default-information originate on Router1. How will this affect the network? 阻止Router1转发有关非直连网络的更新prevents Router1 from forwarding updates about networks that are not directly connected 使网络中的所有路由器都与Router1同步路由更新 causes all routers in the network to synchronize routing updates with Router1 强制Router1成为更新的主要路由器或指定路由器(DR) forces Router1 to become the primary or designated router (DR) for updates 向网络中的所有路由器传播默认路由 propagates the default route to all routers in the network 15 请参见图示。如图所示的网络中同时包含Cisco路由器和非Cisco路由器。JAX路由器上输入了命令debug ip rip。目前所有路由器都运行相同版本的RIP。路由器CHI和路由器ORL无法到达192.168.1.16/28网络。使用什么方法可能解决此问题？2 Refer to the exhibit. The exhibited network contains a mixture of Cisco and non-Cisco routers. The command debug ip rip was entered on the JAX router. All routers are running the same version of RIP. Router CHI and Router ORL are not able to reach the 192.168.1.16/28 network. What is a possible solution to this problem? 在网络中启用水平分割。 Enable split horizon in the network. 在路由器上配置RIPv2。 Configure RIPv2 on routers. 在JAX路由器的RIP配置中添加网络192.168.1.0。 Add network 192.168.1.0 to the RIP configuration on the JAX router. 将JAX Fa0/0配置为被动接口。 Configure JAX Fa0/0 as a passive interface. 启用JAX路由器上的Serial0/0/0接口。Enable the Serial0/0/0 interface on the JAX router. 将JAX路由器Fa0/0接口的IP地址更改为192.168.1.1/24。Change the IP address on the Fa0/0 interface of the JAX router to 192.168.1.1/24.16、为了支持VLSM和CIDR，RFC 1723在RIP消息报头中添加了什么字段？1What field was added to the RIP message header by RFC 1723 to add support for VLSM and CIDR? 子网掩码 目的端口号 地址族标识符 源和目的IP地址 17 请参见图示。如图所示的命令对Router1的RIP更新会产生什么影响？2 Refer to the exhibit. What effect will the commands that are shown have on RIP updates for Router1? 只有第2版更新会发送到255.255.255.255。Only version 2 updates are sent to 255.255.255.255. 只有第2版更新会发送到224.0.0.9。 第1版和第2版更新都会发送到224.0.0.9。 第1版和第2版更新都会发送到255.255.255.255。Both version 1 and version 2 updates are sent to 255.255.255.255. 18 请参见图示。RIPv1是如图所示网络的路由协议。在每台路由器上使用以下命令： Refer to the exhibit. RIPv1 is configured as the routing protocol for the network that is shown. The following commands are used on each router:router ripnetwork 10.0.0.0network 172.16.0.0完成上述配置后，每台路由器的LAN上的用户都无法访问远程LAN。为什么？3 When this configuration is complete, users on the LAN of ea