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CCNA4 思科第四学期final4--3a(第三套题)答案a2012最新答案

1从什么物理位置起，WAN 连接从由用户负责变为由服务提供商负责？非军事区(DMZ)分界点本地环路网云2一名技术人员正编辑ACL 115，并将其重新应用到路由器，在将ACL 重新应用到路由器时向其中添加access-list 115 permit tcp any 172.16.0.0 0.0.255.255 established命令会产生什么结果？会允许所有来自172.16.0.0/16 的流量。

会允许所有发往172.16.0.0/16 的TCP 流量。

会允许任何发送至172.16.0.0/16 的SYN 数据包。

会允许对网络172.16.0.0/16 所发出流量响应。

3请参见图示。

网络管理员对Router1 和Router2 上发出图示中的命令。

但其后在检查路由表时发现，两个路由器均不能获知相邻路由器的LAN 网络。

RIPng配置最可能发生什么问题？串行接口处于不同的子网上。

接口上未启用RIPng 进程。

Router1 和Router2 的RIPng 进程不匹配。

IPv6 RIP 配置中缺少RIPng network命令。

4参见图示。

网络管理员创建一个标准访问控制列表，以禁止从网络192.168.1.0/24 访问网络192.168.2.0/24 并允许所有网络访问Internet。

应该在哪个路由器接口和方向上应用该列表？Fa0/0 接口，入站Fa0/0 接口，出站Fa0/1 接口，入站Fa0/1 接口，出站5系统管理员必须为某个小型远程办公室中的十台主机提供Internet 连接。

ISP 已为该远程办公室分配了两个公有IP 地址。

系统管理员如何配置路由器才能让十位用户全部同时接入Internet？配置DHCP 和静态NAT。

为十名用户配置动态NAT。

为全部十名用户配置静态NAT。

配置带过载的动态NAT。

6请参见图示。

R1 针对内部网络10.1.1.0/24 执行NAT 过载。

主机A 向web 服务器发送了一个数据包。

CCNA第四学期章节测试题

答案：1、D 2、AE 3、BC 4、E 5、B 6、D 7、AEF 8、A 9、A 10、B 11、D 12、B 13、A 14、D 15、AD 16、A 17、ABF 18、BF 19、B 20、C1收集症状以排查网络故障时，哪个步骤可能会牵涉到外部管理员？缩小范围收集可疑设备的症状分析现有症状确定所有权2逻辑网络图中一般有哪两项要素？（选择两项。

）接口标识符连接器类型操作系统版本电缆类型虚电路3请参见图示。

在创建网络文档的过程中应该进行哪两个步骤？（选择两项。

）记录仅在园区网络中发现的设备的相关信息。

记录在整个网络中（包括远程站点）发现的设备的相关信息。

将网络配置表中与拓扑图所示组件相关的任何设备信息记录下来。

仅将网络配置表中与拓扑图所示组件相关的第2 层和第3 层设备信息记录下来。

将网络配置表中与拓扑图所示组件相关的在网络使用高峰期收集的的设备信息记录下来。

4请参见图示。

图中的图表来自HR-1，它是HR 部门使用的唯一一台应用程序服务器。

基线数据收集开始于8 月1 日。

从图表中可确定什么有用信息？HR-1 上的CPU 资源失衡。

需要调整处理周期。

有两个明显的周末处理周期，它们始于周六夜晚，止于周日早上。

基线图表显示HR-1 明显具有处理问题（尽管问题本质尚不清楚）。

HR-1 上的处理负载重复再现，因此可预测。

HR-1 上的CPU 负载因某种原因受到明显影响，但由于信息不足，无法确定是否存在问题。

5请参见图示。

服务器HR 上的一个应用程序不再响应任何客户端请求。

每件事务都取决于数据中心中的多台服务器。

数据中心内的服务器上运行的为全公司提供服务的应用程序均无问题。

员工没有解决此类故障的经验，且对各种应用程序的了解也有限。

哪些初始故障排除步骤体现了自上而下的故障排除方法？检查所有服务器的电缆连接。

检查每块网卡上的连接指示灯是否为绿色。

Ping 每台服务器的本地地址，然后Ping 相关服务器和典型客户端的地址。

计算机四级网络工程师习题库(附参考答案)

计算机四级网络工程师习题库（附参考答案）一、单选题（共80题，每题1分，共80分）1、下列关于生产者消费者的叙述中，哪一个是正确的( )。

A、生产者往缓冲区放产品前要先用B、生产者往缓冲区放产品前要先使用C、生产者往缓冲区放产品前要先使用D、消费者从缓冲区取产品前要先用正确答案：C2、关于XMPP的描述中，正确的是( )。

A、基于XMLB、工作于网络层C、只被微软支持D、腾讯是制定者之一正确答案：A3、关于IM系统的通信协议的描述中，正确的是( )。

A、MSN采用B、323C、QQ采用JABBERD、AOL采用OSCARE、ICQ采用SIMPLE正确答案：C4、关于数据报交换与虚电路交换的描述中，正确的是( )。

A、数据报交换的数据单元中不需要包含源节点与目的节点地址B、虚电路交换需要在源节点与目的节点之间建立一条逻辑连接C、虚电路交换的数据单元中需要包含源节点与目的节点地址D、数据报交换需要在源节点与目的节点之间建立一条物理连接正确答案：B5、关于X.800的描述中，错误的是( )。

A、包含安全服务B、支持可逆加密C、将攻击分为主动和被动攻击D、保证系统的绝对安全正确答案：D6、简单页式存储管理方案中，若地址用 m 个二进制位表示，页内地址部分占 n 个二进制位，则最大允许进程有多少个页面( )。

A、2 mB、2 (m-n)C、2 nD、2 (n-1)正确答案：B7、进程运行过程中，导致进程从运行态转换为就绪态的典型事件是( )。

A、发生了缺页中断B、时间片到C、程序出错D、访问的数据没有准备好正确答案：B8、邮件服务器之间传递邮件通常使用的协议为( )。

A、SNMPB、SMTPC、TelnetD、HTTP正确答案：B9、int main(){Printf("Hello World\n");Fork();Printf("Hello World\n");}在 UNIX 操作系统中正确编译链接后，其正确的运行结果是( )。

CCNA第四学期官方章节考试题之第四学期《Final_Examination》(附答案)

公司与AA2SSH存在不正确的访问控制列表条目。

访问列表中的必须在会防止以明文传输登录信息如果身份验证失败，则会断开PPP 会话连接会发起双向握手容易遭受回送攻击4命令show frame-relay map的输出如下：Serial 0 (up): ip 192.168.151.4 dlci 122, dynamic, broadcast, status defined, active 下列哪三种说法正确描述了所示内容的意义？（选择三项。

）192.168.151.4代表远程路由器的IP 地址192.168.151.4代表本地串行接口的IP 地址DLCI 122代表远程串行接口DLCI 122代表用于连接远程地址的本地编号broadcast表示动态路由协议（例如RIP v1）可通过此PVC 发送数据包active表明ARP 进程正在工作5路由器的SDM 主页会显示哪三点信息？（选择三项。

）ARP 缓存闪存的总容量和可用容量路由表已配置的LAN 接口的数量是否配置了DHCP 服务器该LAN 中路由器的数量6从非军事区分界点本地环路网云确保在确认确保路由器上有通向下列哪三种说法正确描述了CSU/DSU调制解调器用于端接本地数字环路。

CSU/DSU调制解调器用于端接本地模拟环路。

路由器通常被视为路由器通常被视为10在链路质量测试完毕后，路由器在协商第LCPNCP它会被丢弃。

它会被放到队列中，直到主机它会被转换，源端口号保持为它会被分配其端口范围内的第一个可用端口号。

交换虚电路的相关信息将DLCI 映射到网络地址提供流量控制提供错误通知提供拥塞通知发送keepalive 数据包以检验PVC 的工作情况14请参见图示。

下列说法中哪三项正确？（选择三项。

）启用了NAT 过载。

启用了动态NAT。

地址转换会失败。

接口配置不正确。

地址为192.168.1.255 的主机将被转换。

进入0/0/2 接口的流量先被转换，然后才流出串行接口0/0/0。

CCNA4 思科第四学期final4--1a(第一套题)答案b2012最新答案

25如果将命令ip dhcp excluded-address 10.10.4.1 10.10.4.5添加到配置为DHCP 服务器的本地路由器配置中，结果是什么？该路由器将丢弃发往10.10.4.1 和10.10.4.5 的流量。

不会路由地址处于10.10.4.1 到10.10.4.5 之间的客户端所发出的流量。

DHCP 服务器不会分配10.10.4.1 到10.10.4.5 之间的地址。

该路由器将忽略来自地址处于10.10.4.1 到10.10.4.5 之间的DHCP 服务器的流量。

26配置帧中继连接时，在下列哪种情况下应使用frame-relay map命令？当远程路由器的品牌不是Cisco 时当本地路由器配置有子接口时当使用全局有效的而非本地有效的DLCI 时当本地路由器与远程路由器使用不同的LMI 协议时27请参见图示。

下列关于WAN 交换设备的说法中哪项正确？它使用多端口网间设备交换WAN 中的帧中继、ATM 或X.25 等流量。

它提供网际互连和用于连接服务提供商网络的WAN 接入接口端口。

它为数字信号提供端接并通过纠错和线路监控技术确保连接的完整性。

它将计算机产生的数字信号转换为可以在公共电话网络的模拟线路上传输的语音频率。

28下列哪两项是可用于PPP 配置的LCP 选项？（选择两项。

）EAPCHAPIPCPCDPCP多链路29下列有关通配符掩码的说法中哪项正确？将子网掩码取反码必定能得到通配符掩码。

通配符掩码中以"1" 标识网络或子网位。

通配符掩码和子网掩码执行相同的功能。

在通配符掩码中碰到"0" 时，必须检查IP 地址位。

30请参见图示。

分支A 有一台Cisco 路由器，分支B 有一台使用IETF 封装的非Cisco 路由器。

输入图中所示的命令后，R2 和R3 无法建立PVC。

R2 LMI 的类型是Cisco，R3 LMI 的类型是ANSI。

CCNA第四学期官方章节考试题之4.5、《ACL》》（附答案）.doc

1有关下列扩展ACL 的说法中哪两项正确？（选择两项。

）access-list 101 deny tcp 172.16.3.0 0.0.0.255 any eq 20 access-list 101 deny tcp 172.16.3.0 0.0.0.255 any eq 21 access-list 101 permit ip any any拒绝从网络172.16.3.0/24 始发的所有FTP 流量。

会隐含拒绝所有流量。

会拒绝发往网络172.16.3.0/24 的所有FTP 流量。

会拒绝从网络172.16.3.0/24 始发的所有Telnet 流量。

会允许从网络172.16.3.0 始发的 Web 流量。

2如果数据包未与ACL 中的任何语句匹配，则会如何处理该数据包？会将该数据包放置在缓冲区中，并在删除该ACL 后转发该数据包。

会将该数据包连同一则错误通知消息发回给源地址。

列表末尾的隐含permit any语句会允许该数据包通过。

列表末尾的隐含deny any语句会导致该数据包被丢弃。

3请参见图示。

ACL 101 中的"deny ip 64.100.0.0 0.0.7.255 any" 语句发现了 35 个匹配项，最可能的解释是什么？内部网络中的一名用户伪造了一台Internet 主机并正在向该主机发送流量，该主机也正在响应。

Internet 上的一名用户伪造了内部网络中的一个主机地址，并正在尝试向内部网络发送数据包。

一台Internet 主机正在反复要求内部网络发送流量。

内部网络中的一台主机正在反复要求Internet 发送流量。

4标准访问控制列表应该放置在哪里？靠近源地址靠近目的地址在以太网端口上在串行端口上5Cisco 标准ACL 是如何过滤流量的？通过目的UDP 端口通过协议类型通过源IP 地址通过源UDP 端口通过目的IP 地址6ACL 可使用哪三种参数来过滤流量？（选择三项。

CCNA第四学期期末考试答案

1、如果将命令ip dhcp excluded-address 10.10.4.1 10.10.4.5添加到配置为DHCP 服务器的本地路由器配置中，结果是什么？该路由器将丢弃发往10.10.4.1 和10.10.4.5 的流量。

不会路由地址处于10.10.4.1 到10.10.4.5 之间的客户端所发出的流量。

DHCP 服务器不会分配10.10.4.1 到10.10.4.5 之间的地址。

该路由器将忽略来自地址处于10.10.4.1 到10.10.4.5 之间的DHCP 服务器的流量。

2、请参见图示。

连接到Fa0/0 的主机无法从此DHCP 服务器获取IP 地址。

debug ip dhcp server命令"DHCPD: there is no address pool for 192.168.1.1"。

问题出在哪里？DHCP 地址池中排除了地址192.168.1.1。

192Network 的地址池不正确。

网络地址池的默认路由器不正确。

地址192.168.1.1 已经用在接口Fa0/0 上。

3、请参见图示。

R1 针对内部网络10.1.1.0/24 执行NAT 过载。

主机A 向web 服务器发送了一个数据包。

务器返回的数据包的目的IP 地址是什么？10.1.1.2:1234172.30.20.1:1234172.30.20.1:3333192.168.1.2:804、请参见图示。

网络管理员对Router1 和Router2 上发出图示中的命令。

但其后在检查路由表时发现，两个路由器均不能获知相邻路由器的LAN 网络。

RIPng 配置最可能发生什么问题？串行接口处于不同的子网上。

接口上未启用RIPng 进程。

未配置RIPng 网络命令。

Router1 和Router2 的RIPng 进程不匹配。

5、请参见图示。

使用default-router和dns-server命令指定的TCP/IP 配置信息是如何获得的？TCP/IP 信息先转发至10.0.1.3，再提供给DHCP 客户端。

CCNA4思科第四学期第4最新答案

思科练习第四学期窗体底端1窗体顶端使用 Cisco AutoSecure 有哪两个好处？（选择两项。

）管理员可通过它来精确控制各种服务的启用和禁用情况。

它可提供立即禁用非关键系统进程和服务的功能。

它可自动将路由器配置为与 SDM 协同工作。

它可确保与您网络中的其它设备充分兼容。

它使管理员无需了解 Ci sco I OS 软件的所有功能即可配置安全策略。

窗体底端2窗体顶端用户无法访问公司服务器。

系统日志显示服务器运行缓慢，因为它正在收到具有高优先级的虚假服务请求。

这是什么类型的攻击？侦测访问DoS蠕虫病毒特洛伊木马窗体底端3窗体顶端下列哪两种说法定义了在网络中启用 DNS 服务所带来的安全风险？（选择两项。

）默认情况下，域名查询被发送到广播地址 255.255.255.255。

DNS 域名查询需要在所有路由器的以太网接口上启用ip directed-broadcast命令。

在一台路由器上使用全局配置命令ip nam e-server会在网络中的所有路由器上启用 DNS 服务。

基本 DNS 协议不提供身份验证或完整性保证。

路由器配置不提供用于设置主 DNS 服务器和备份 DNS 服务器的选项。

窗体底端4窗体顶端网络管理员在试图通过 TFTP 服务器升级 Ci sco I OS 映像前，必须检验哪两项？（选择两项。

）使用show h osts命令检验 TFTP 服务器的名称。

使用tftpdnld命令检验 TFTP 服务器是否正在运行。

使用show version命令检验映像的校验和是否有效。

使用ping命令检验路由器与 TFTP 服务器之间的连通性。

使用show fl ash命令检验闪存是否具有足够空间容纳新的 Cisco IOS 映像。

窗体底端5窗体顶端下列关于网络安全的说法中哪两项正确？（选择两项。

）保护网络免受内部威胁侵害具有较低的优先级，因为由公司员工带来的安全风险较低。

无论是能自己编写攻击代码的资深黑客，还是从 Internet 下载攻击程序的入门攻击者都可能对网络安全造成严重威胁。

CCNA4 思科第四学期 v4.0 EWAN Chapter 6最新答案

窗体顶端微波接入全球互通 (WiM AX) 通信技术有哪两项特点？（选择两项。

）支持使用网状技术的市政无线网络可覆盖的面积多达 7,500 平方公里支持点对点链路，但不支持全移动蜂窝式接入通过高带宽连接直接连接到 Internet工作速度比 Wi-Fi 低，但支持的用户更多窗体底端2窗体顶端安全 VPN 有哪三项主要功能？（选择三项。

）记帐身份验证授权数据可用性数据机密性数据完整性窗体底端3窗体顶端请参见图示。

所有用户都拥有访问企业网络的合法目的和必要权限。

根据图中所示的拓扑，哪些地点可与企业网络建立 VPN 连接？地点 C、D 和 E 可支持 VPN 连接。

地点 A 和 B 需要在网络边缘另外安装 PIX 防火墙装置。

地点 C 和 E 可支持 VPN 连接。

地点 A、B 和 D 需要在网络边缘另外安装 PIX 防火墙装置。

地点 A、B、D 和 E 可支持 VPN 连接。

地点 C 需要在网络边缘另外安装路由器。

所有地点均可支持 VPN 连接。

窗体底端4窗体顶端下列关于 DSL 的说法中哪两项正确？（选择两项。

）用户连接到共享介质上使用 RF 信号传输本地环路最长可达 3.5 英里 (5.5km)物理层和数据链路层由 D OCSIS 定义用户连接通过 C O 处的 DSL AM 汇聚窗体底端5窗体顶端VPN 通过哪两种方法实现数据传输的机密性？（选择两项。

）数字证书加密封装哈希密码窗体底端6窗体顶端可使用哪三种加密协议加强 VPN 的数据传输机密性？（选择三项。

）AESDESAH哈希MPLSRSA窗体底端7窗体顶端下列哪项是对称密钥加密的例子？Diffie-Hellman数字证书预共享密钥RSA 签名窗体底端8窗体顶端技术人员应要求为远程工作人员配置宽带连接。

技术人员接到指示，连接所需的所有升级和下载工作都必须使用现有电话线路进行。

应该使用哪种宽带技术？电缆DSLISDNPOTS窗体底端9窗体顶端研究过远程工作人员常用的远程连接方式后，网络管理员决定实施宽带远程接入以通过公共 Interne t 建立 VPN 连接。

ccna第四学期4

1下列关于网络安全的说法中哪两项正确？（选择两项。

）保护网络免受内部威胁侵害具有较低的优先级，因为由公司员工带来的安全风险较低。

无论是能自己编写攻击代码的资深黑客，还是从Internet下载攻击程序的入门攻击者都可能对网络安全造成严重威胁。

假设一家公司将其web服务器部署在防火墙之外，并充分备份web服务器，则无需采取其它安全措施来保护web服务器，因为即使它被攻击了也不会造成损失。

公众认可的网络操作系统（例如UNIX）和网络协议（例如TCP/IP）可采用默认设置工作，因为它们没有内在的安全缺陷。

保护网络设备免受水电等外在因素造成的物理破坏是安全策略的必要组成部分。

Option 2 and Option 5 are correct.2下列关于网络攻击的陈述，哪两项是正确的？（选择两项。

）强网络口令可防范大多数DoS攻击。

蠕虫需要人的参与才能扩散，而病毒不需要。

侦测攻击本质上始终是电子攻击，例如ping扫描或端口扫描。

暴力攻击会尝试使用字符集组合来搜索每个可能的口令。

内部设备不应该完全信任DMZ中的设备，应该对DMZ和内部设备之间的通信进行身份验证以防范端口重定向等攻击。

Option 4 and Option 5 are correct.3用户无法访问公司服务器。

系统日志显示服务器运行缓慢，因为它正在收到具有高优先级的虚假服务请求。

这是什么类型的攻击？侦测访问DoS蠕虫病毒特洛伊木马2 points for Option 34IT主管发起了一项活动，旨在提醒用户避免打开来源可疑的电子邮件。

该IT主管意在保护用户免受哪种攻击？DoSDDoS病毒访问侦测2 points for Option 35下列关于预防网络攻击的说法中哪两项正确？（选择两项。

）现代服务器和PC操作系统具有可以信赖的默认安全设置。

入侵防御系统可以记录可疑的网络活动，但在没有用户干预的情况下无法对抗正在进行的攻击。

物理安全威胁的防范包括控制对设备控制台端口的访问、标识关键电缆、安装UPS系统以及提供温湿控制。

ccna测试题及答案

ccna测试题及答案CCNA测试题及答案一、选择题1. 在Cisco设备上，以下哪个命令用于查看当前的路由表？A. show ip routeB. show running-configC. show interface statusD. show version答案：A2. 以下哪个协议用于在网络中自动发现其他设备？A. ARPB. CDPC. ICMPD. TCP答案：B3. 以下哪个命令用于配置Cisco设备上的接口？A. configure terminalB. interfaceC. ip addressD. hostname答案：A二、填空题4. 在Cisco设备上，使用命令_________可以查看接口的配置信息。

答案：show interface5. 静态路由配置中，_________命令用于指定下一跳地址。

答案：ip route6. 动态路由协议可以自动适应网络变化，其中_________是最常见的一种。

答案：RIP（路由信息协议）三、简答题7. 请简述VLAN（虚拟局域网）的作用。

答案：VLAN是一种将局域网内不同物理位置的设备划分为同一逻辑网络的技术，主要用于隔离广播域，提高网络的安全性和效率。

8. 描述交换机和路由器在网络中的基本功能。

答案：交换机主要用于局域网内部，通过MAC地址表来转发数据帧，实现数据包在局域网内的快速交换。

路由器则工作在网络层，使用IP地址来转发数据包，连接不同的网络，并进行路径选择。

四、计算题9. 假设一个子网掩码为255.255.255.192，计算这个子网的可用IP地址范围。

答案：可用IP地址范围为192.168.1.0到192.168.1.62（包含两端）。

五、实验题10. 请根据以下配置文件，列出Router1的接口配置信息。

```Router1show running-configinterface FastEthernet0/0ip address 192.168.1.1 255.255.255.0duplex autospeed auto!interface FastEthernet0/1no ip addressshutdown!interface Serial0/0/0ip address 10.0.0.1 255.255.255.252clock rate 64000!router ospf 1network 192.168.1.0 0.0.0.255 area 0network 10.0.0.0 0.0.0.3 area 0!```答案：- FastEthernet0/0: IP地址为192.168.1.1，子网掩码为255.255.255.0，双工模式和速度均为自动。

思科答案CCNA4-4

1.下列关于网络安全的说法中哪两项正确？（选择两项。

）25保护网络免受内部威胁侵害具有较低的优先级，因为由公司员工带来的安全风险较低。

无论是能自己编写攻击代码的资深黑客，还是从Internet 下载攻击程序的入门攻击者都可能对网络安全造成严重威胁。

假设一家公司将其web 服务器部署在防火墙之外，并充分备份web 服务器，则无需采取其它安全措施来保护web 服务器，因为即使它被攻击了也不会造成损失。

公众认可的网络操作系统（例如UNIX）和网络协议（例如TCP/IP）可采用默认设置工作，因为它们没有内在的安全缺陷。

保护网络设备免受水电等外在因素造成的物理破坏是安全策略的必要组成部分。

2.下列关于网络攻击的陈述，哪两项是正确的？（选择两项。

）45强网络口令可防范大多数DoS 攻击。

蠕虫需要人的参与才能扩散，而病毒不需要。

侦测攻击本质上始终是电子攻击，例如ping 扫描或端口扫描。

暴力攻击会尝试使用字符集组合来搜索每个可能的口令。

内部设备不应该完全信任DMZ 中的设备，应该对DMZ 和内部设备之间的通信进行身份验证以防范端口重定向等攻击。

3.用户无法访问公司服务器。

系统日志显示服务器运行缓慢，因为它正在收到具有高优先级的虚假服务请求。

这是什么类型的攻击？3侦测访问DoS蠕虫病毒特洛伊木马4.IT 主管发起了一项活动，旨在提醒用户避免打开来源可疑的电子邮件。

该IT 主管意在保护用户免受哪种攻击？3DoSDDoS病毒访问侦测5.下列关于预防网络攻击的说法中哪两项正确？（选择两项。

）35现代服务器和PC 操作系统具有可以信赖的默认安全设置。

入侵防御系统可以记录可疑的网络活动，但在没有用户干预的情况下无法对抗正在进行的攻击。

物理安全威胁的防范包括控制对设备控制台端口的访问、标识关键电缆、安装UPS 系统以及提供温湿控制。

防止网络钓鱼攻击的最好方法是采用防火墙设备。

更改默认的用户名和口令并禁用或取消不必要的服务有助于加强设备安全性。

CCNA 4 Final Exam V4.0 Answers

1. What functionality do access control lists provide in the implementation of dynamic NAT on a Cisco router?define which addresses can be translateddefine which addresses are assigned to a NAT pooldefine which addresses are allowed out the routerdefine which addresses can be accessed from the inside network2. Which three guidelines would help contribute to creating a strong password policy? (Choose three.)Once a good password is created, do not change it.Deliberately misspell words when creating passwords.Create passwords that are at least 8 characters in length.Use combinations of upper case, lower case, and special characters.3.Refer to the exhibit. Every time the administrator reboots this router, the boot process ends in setup mode. What is a possible problem?There is insufficient RAM for the IOS to load on this router.A password recovery process should be done on this router.The bootstrap version and the version of the IOS are different.The IOS image is damaged and must be reloaded using tftpdnld.The configuration register is set to ignore the startup configuration.4. Which option correctly defines the capacity through the local loop guaranteed to a customer by the service provider?BEDECIRCBIR5.Refer to the exhibit. A host connected to Fa0/0 is unable to acquire an IP address from the DHCP server. The output of the debug ip dhcp server command shows "DHCPD: there is no address pool for 10.1.1.1". What is the problem?The 10.1.1.1 address is already configured on Fa0/0.The default router for the 10Network pool is incorrect.The ip helper-address must be added to Fa0/0 interface.The pool of addresses for the 10Network pool is incorrect.6. Which data link layer encapsulation protocol is used by default for serial connections between two Cisco routers?ATMFrame RelayHDLCPPPSDLCRefer to the exhibit. Which statement correctly describes how Router1 processes an FTP request that enters interface s0/0/0 and is destined for an FTP server at IP address 192.168.1.5?The router matches the incoming packet to the statement that was created by the access-list 201 deny icmp 192.168.1.0 0.0.0.255 any command, continues comparing the packet to the remaining statements in ACL 201 to ensure that no subsequent statements allow FTP, and then the router drops the packet.The router reaches the end of ACL 101 without matching a condition and drops the packet because there is no statement that was created by the access-list 101 permit ip any any command.The router matches the incoming packet to the statement that was created by the access-list 101 permit ip any 192.168.1.0 0.0.0.255 command and allows the packet into the router.It matches the incoming packet to the statement that was created by the access-list 201 permit ip any any command and allows the packet into the router.8. Compared with IDS systems, what can IPS systems do to provide further protection of computer systems?detect potential attacksstop the detected attack from executingupdate OS patches for computer systemsscan computer systems for viruses and spyware9. Which IEEE 802.16 broadband wireless technology allows users to connect to the ISP at speeds comparable to DSL and cable?Wi-FisatelliteWiMAXMetro Ethernet10. A network administrator has changed the VLAN configurations on his network switches over the past weekend. How can the administrator determine if the additions and changes improved performance and availability on the company intranet?Conduct a performance test and compare with the baseline that was established previously.Interview departmental secretaries and determine if they think load time for web pages has improved.Determine performance on the intranet by monitoring load times of company web pages from remote sites.Compare the hit counts on the company web server for the current week to the values that were recorded in previous weeks.11.Refer to the exhibit. What is the meaning of the term dynamic in the output of the command?The bandwidth capability of the interface increases and decreases automatically based on BECNs.The Serial0/0/1 interface acquired 172.16.3.1 from a DHCP server.The mapping between DLCI 100 and 172.16.3.1 was learned through Inverse ARP.DLCI 100 will automatically adapt to changes in the Frame Relay cloud.12. Which type of ACL will permit traffic inbound into a private network only if an outbound session has already been established between the source and destination?extendedreflexivestandardtime-based13. Which two statements are true about IPv6 link local addresses? (Choose two.)They begin with the 2000::/3 prefix.They begin with the FE80::/10 prefix.They are assigned by IANA to an organization.They must be manually configured by the administrator.They are assigned to a host by a stateless autoconfiguration process.14. A company is looking for a WAN solution to connect its headquarters site to four remote sites. What are two advantages that dedicated leased lines provide compared to a shared Frame Relay solution? (Choose two.)reduced jitterreduced costsreduced latencythe ability to burst above guaranteed bandwidththe ability to borrow unused bandwidth from the leased lines of other customers15.Refer to the exhibit. A network administrator is trying to connect R1 remotely to make configuration changes. Based on the exhibited command output, what will be the result when attempting to connect to R1?failure to connect due to Telnet not being enabledfailure to connect due to incomplete configuration for Telneta successful connection and ability to make configuration changesa successful connection but inability to make configuration changes because of the absence of an enable secret password16. What are two effective measures for securing routers? (Choose two.)Protect all active router interfaces by configuring them as passive interfaces.Configure remote administration through VTY lines for Telnet access. Use quotes or phrases to create pass phrases.Disable the HTTP server service.Enable SNMP traps.17. An issue of response time has recently arisen on an application server. The new release of a software package has also been installed on the server. The configuration of the network has changed recently. To identify the problem, individuals from both teams responsible for the recent changes begin to investigate the source of the problem. Which statement applies to this situation?Scheduling will be easy if the network and software teams work independently.It will be difficult to isolate the problem if two teams are implementing changes independently.Results from changes will be easier to reconcile and document if each team works in isolation.Only results from the software package should be tested as the network is designed to accommodate the proposed software platform.Refer to the exhibit. From the output of the show interfaces and ping commands, at which layer of the OSI model is a fault indicated?applicationtransportnetworkdata linkphysical19. Which technology is used to dynamically map next hop, network layer addresses to virtual circuits in a Frame Relay network?Inverse ARPLMIDLCI20. An administrator learns of an e-mail that has been received by a number of users in the company. This e-mail appears to come from the office of the administrator. The e-mail asks the users to confirm their account and password information. Which type of security threat does this e-mail represent?crackingphishingphreakingspamming21.Refer to the exhibit. Which data transmission technology is being represented?TDMPPPHDLCSLIP22.Refer to the exhibit. Results of the show vlan and show vtp status commands for switches S1 and S2 are displayed in the exhibit. VLAN 11 was created on S1. Why is VLAN 11 missing from S2?There is a Layer 2 loop.The VTP domain names do not match.Only one switch can be in server mode.S2 has a higher spanning-tree priority for VLAN 11 than S1 does.23. What is the result of adding the global command servicepassword-encryption to the configuration of a router?Line passwords are encrypted with type 7 encryption.Enable passwords are encrypted with type 5 encryption.All services must provide an encrypted password to function.Only encrypted messages are allowed for router communication.24. While troubleshooting a problem with an e-mail server, an administrator observes that the switch port used by the server shows "up, line protocol up". The administrator cannot ping the server. At which layer of the OSI model is the problem most likely to be found?application layernetwork layerdata link layerphysical layer25. Where does a service provider assume responsibility from a customer for a WAN connection?local loopDTE cable on routerdemarcation pointdemilitarized zone26. What will be the result of adding the command ip dhcp excluded-address 192.168.24.1 192.168.24.5to the configuration of a local router that has been configured as a DHCP server?Traffic that is destined for 192.168.24.1 and 192.168.24.5 will be dropped by the router.Traffic will not be routed from clients with addresses between192.168.24.1 and 192.168.24.5.The DHCP server will not issue the addresses ranging from 192.168.24.1 to 192.168.24.5.The router will ignore all traffic that comes from the DHCP servers with addresses 192.168.24.1 and 192.168.24.5.27.Refer to the exhibit. Partial results of the show access-lists and show ip interface FastEthernet 0/1 commands for router Router1 are shown. There are no other ACLs in effect. Host A is unable to telnet to host B. Which action will correct the problem but still restrict other traffic between the two networks?Apply the ACL in the inbound direction.Apply the ACL on the FastEthernet 0/0 interface.Reverse the order of the TCP protocol statements in the ACL.Modify the second entry in the list to permit tcp host 172.16.10.10 any eq telnet .28.Refer to the exhibit. The corporate network that is shown has been assigned network 172.16.128.0/19 for use at branch office LANs. If VLSM is used, what mask should be used for addressing hosts at Branch4 with minimal waste from unused addresses?/19/20/21/22/23/2429.Refer to the exhibit. RIPv2 has been configured on all routers in the network. Routers R1 and R3 have not received any RIP routing updates. What will fix the issue?Enable RIP authentication on R2.Issue the ip directed-broadcast command on R2.Change the subnet masks to 10.11.12.0/8 and 172.16.40.0/16 on R2.Enable CDP on R2 so that the other routers will receive routing updates.30.Refer to the exhibit. This serial interface is not functioning correctly. Based on the output shown, what is the most likely cause?improper LMI typeinterface resetPPP negotiation failureunplugged cable31. Which statement is true about PAP in the authentication of a PPP session?PAP uses a two-way handshake.The password is unique and random.PAP conducts periodic password challenges.PAP uses MD5 hashing to keep the password secure.32. An administrator is configuring a dual stack router with IPv6 and IPv4 using RIPng. The administrator receives an error message when trying to enter the IPv4 routes into RIPng. What is the cause of the problem?When IPv4 and IPv6 are configured on the same interface, all IPv4 addresses are over-written in favor of the newer technology.Incorrect IPv4 addresses are entered on the router interfaces.RIPng is incompatible with dual-stack technology.IPv4 is incompatible with RIPng.33. What is tunneling?using digital certificates to ensure that data endpoints are authentic creating a hash to ensure the integrity of data as it traverses a networkusing alternate paths to avoid access control lists and bypass security measuresencapsulating an entire packet within another packet for transmission over a network34. Which statement is true about NCP?Link termination is the responsibility of NCP.Each network protocol has a corresponding NCP.NCP establishes the initial link between PPP devices.NCP tests the link to ensure that the link quality is sufficient. 35.Refer to the exhibit. A network administrator is creating a prototype to verify the new WAN design. However, the communication between the two routers cannot be established. Based on the output of the commands, what can be done to solve the problem?Replace the serial cable .Replace the WIC on RA.Configure RA with a clock rate command.Issue a no shutdown interface command on RB.36.Refer to the exhibit. Based on the output as shown, which two statements correctly define how the router will treat Telnet traffic that comes into interface FastEthernet 0/1? (Choose two).Telnet to 172.16.10.0/24 is denied.Telnet to 172.16.20.0/24 is denied.Telnet to 172.16.0.0/24 is permitted.Telnet to 172.16.10.0/24 is permitted.Telnet to 172.16.20.0/24 is permitted.37. Which Frame Relay flow control mechanism is used to signal routers that they should reduce the flow rate of frames?DEBECIRFECNCBIR38.Refer to the exhibit. A network administrator configures a standard access control list on Router1 to prohibit traffic from the 192.168.0.0/24 network from reaching the Internet. The access control list also permits traffic from the 192.168.0.0/24 network to reach the 192.168.1.0/24 network. On which interface and in which direction should the access control list be applied?interface Fa0/0, inboundinterface Fa0/0, outboundinterface S0/0/0, inboundinterface S0/0/0, outbound39. Which configuration on the vty lines provides the best security measure for network administrators to remotely access the core routers at headquarters?Answer: 3nd option 40.Refer to the exhibit. What can be concluded from the exhibited output of the debug ip nat command?The 10.1.1.225 host is exchanging packets with the 192.168.0.10 host.The native 10.1.200.254 address is being translated to 192.168.0.10.The 192.168.0.0/24 network is the inside network.Port address translation is in effect.41. A network administrator is instructing a technician on best practices for applying ACLs. Which suggestion should the administrator provide?Named ACLs are less efficient than numbered ACLs.Standard ACLs should be applied closest to the core layer.ACLs applied to outbound interfaces are the most efficient.Extended ACLs should be applied closest to the source that is specified by the ACL.42.Refer to the exhibit. Headquarters is connected through the Internet to branch office A and branch office B. Which WAN technology would be best suited to provide secure connectivity between headquarters and both branch offices?ATMVPNISDNFrame Relaybroadband DSL43. Which three physical network problems should be checked when a bottom-up troubleshooting approach has been chosen to troubleshoot network performance? (Choose three.)cable connectivityhigh collision countsSTP failures and loopsaddress mapping errorshigh CPU utilization ratesexcess packets that are filtered by the firewall44.Refer to the exhibit. A network administrator is attempting to configure a Frame Relay network. The administrator enters the commands as shown in the exhibit on R2, but the Frame Relay PVCs are inactive. What is the problem?The incorrect DLCI numbers are being configured on R2.The S0/0/0 interface on R2 needs to be point-to-point.The frame-relay map commands are missing the cisco keyword at the end.A single router interface cannot connect to more than one Frame Relay peer at a time.45. Which IP address and wildcard mask would be used in an ACL to block traffic from all hosts on the same subnet as host 192.168.16.43/28?access-list 10 deny 192.168.16.0 0.0.0.31access-list 10 deny 192.168.16.16 0.0.0.31access-list 10 deny 192.168.16.32 0.0.0.16access-list 10 deny 192.168.16.32 0.0.0.15access-list 10 deny 192.168.16.43 0.0.0.1646. Which combination of Layer 2 protocol and authentication should be used to establish a link without sending authentication information in plain text between a Cisco and a non-Cisco router?PPP with PAPPPP with CHAPHDLC with PAPHDLC with CHAP47. When would the multipoint keyword be used in Frame Relay PVCs configuration?when global DLCIs are in usewhen using physical interfaceswhen multicasts must be supportedwhen participating routers are in the same subnet48. A network technician analyzes the network and notices late collisions. The collisions occur accompanied by jabber that originates from the server. What is the likely cause of the problem?faulty switch portweb server CPU overloadfaulty NIC in the web servermisconfiguration of web server services49.Refer to the exhibit. R1 is performing NAT overload for the 10.1.1.0/24 inside network. Host A has sent a packet to the web server. What is the destination IP address of the return packet from the web server?10.1.1.2:1234172.30.20.1:1234172.30.20.1:3333192.168.1.2:8050.Refer to the exhibit. All devices are configured as shown in the exhibit. PC1 is unable to ping the default gateway. What is the cause of the problem?The default gateway is in the wrong subnet.STP has blocked the port that PC1 is connected to.Port Fa0/2 on S2 is assigned to the wrong VLAN.S2 has the wrong IP address assigned to the VLAN30 interface.51. When Frame Relay encapsulation is used, what feature provides flow control and exchanges information about the status of virtual circuits?LCPLMIDLCIInverse ARP52. A network administrator is tasked with maintaining two remote locations in the same city. Both locations use the same service provider and have the same service plan for DSL service. When comparing download rates, it is noticed that the location on the East side of town has a faster download rate than the location on the West side of town. How can this be explained?The West side has a high volume of POTS traffic.The West side of town is downloading larger packets.The service provider is closer to the location on the East side.More clients share a connection to the DSLAM on the West side.。

CCNA+第四学期章节测试题答案c4第三章

下列哪项最准确地描述了采用帧中继与采用租用线路或 ISDN 服务相比的优势？客户可以更精确地定义其虚电路需求，且带宽需求之间的差别可低至 64 kbps。

客户只需支付包含本地环路和网络链路的端对端连接的费用。

客户只需支付本地环路以及网络提供商所提供的带宽的费用。

连接新站点时，所需的新电路安装成本要低于 ISDN 拨号的成本或因租用服务而添加额外硬件的成本。

帧中继技术使用哪两种方法处理包含错误的帧？（选择两项。

）帧中继服务依靠上层协议来处理错误恢复工作。

它要求接收设备请求发送方重新传输错误帧。

设置帧中的 FECN、BECN 和 DE 位以尽量减少错误。

接收设备会丢弃所有包含错误的帧而不会通知发送方。

帧中继交换机会通知发送方检测到了错误。

哪种说法是对数据链路连接标识符 (DLCI) 的最佳描述？用于标识通过帧中继网络连接的目的路由器的本地地址用于标识虚电路的具有本地意义的地址用于标识路由器和帧中继交换机之间的接口的逻辑地址用于标识 DCE 的逻辑地址在帧中继网络两个 DTE 之间创建的是什么？ISDN 电路有限访问电路交换并行电路虚电路在帧中继网络中，下列哪两项使路由器可将数据链路层地址映射到网络层地址？（选择两项。

）ARP在线代理|网页代理|代理网页|RARP代理ARP逆向ARPLMI 状态消息ICMP请参见图示。

从路由器 Peanut 向地址 192.168.50.10 发出了一次 ping 命令。

发送该 ping 命令时将使用什么 DLCI？110115220225请参见图示。

子接口 S0/0.110 上的点对点配置对路由器的运作有什么影响？它有助于节约 IP 地址。

在线代理|网页代理|代理网页|它与多个物理接口建立多个 PVC 连接。

它既消除了水平分割问题，又不增大出现路由环路的可能性。

它需要在子接口上配置encapsulation命令。

当帧中继交换机检测到队列中含有过多待处理帧时，会进行哪三项操作？（选择三项。

(完整版)CCNA四考试答案

8
窗体顶端
一家新的公司需要满足特定需要的数据网络。网络必须为分布在广阔地域中的销售人员提供低成本连接。哪两种WAN基础设施可以满足要求？（请选择两项。）
公共基础设施
私有基础设施
Internet
专用
卫星
窗体底端
答案：1和3
解析：Internet上的VPN为远程用户提供低成本的安全连接。VPN部署在Internet公共基础设施上。
3
窗体顶端
以下哪项描述了WAN的特征？
WAN和LAN在同一地理范围内运行，但有串行链路。
WAN网络归运营商所有。
所有串行链路均被视为WAN连接。
WAN可提供到园区主干网的终端用户网络连接。
窗体底端
答案：2
解析：WAN可用于将企业LAN互连到远程分支机构站点LAN和远程工作人员站点。WAN归运营商所有。虽然WAN连接一般通过串行接口实现，但并不是所有串行链路均连接至WAN。LAN（而非WAN）可在组织中提供终端用户网络连接。
12
窗体顶端
哪两种技术使用PSTN网络来提供Internet连接？（请选择两项。）
ATM
ISDN
MPLS
拨号
帧中继
窗体底端
答案：2和4
解析：拨号和ISDN使用PSTN网络来提供WAN连接。ATM、MPLS和帧中继需要服务提供商构建特定网云来支持每种技术。
13
窗体顶端
公司需要互连城市区域中的多个分支机构。网络工程师正在寻找可提供高速融合流量（包括同一网络基础设施中的语音、视频和数据）的解决方案。公司还希望能够轻松集成到其办公地点的现有LAN基础设施中。应该推荐哪种技术？
解析：Link-establishment帧负责建立和配置链路。Link-maintenance帧负责管理和调试链路。Link-termination帧负责终止链路。

CCNA 4 - Final Exam (C)

CCNA 4 - Final Exam (C)Posted by beotron at 9:23 PM1. Which of the following describes the roles of devices in a WAN? (Choose three.)• A CSU/DSU terminates a digital local loop.• A modem terminates a digital local loop.• A CSU/DSU terminates an analog local loop.• A modem terminates an analog local loop.• A router is commonly considered a DTE device.• A router is commonly considered a DCE device.2. What value in the address field of a Frame Relay header identifies the destination of the frame? • CIR• DE• DLCI• ISDN• FRAD• PVC3. The serial PPP link between the Left and Right routers is configured as shown in the diagram. Which configuration issue explains why the link is unable to establish a PPP session?• The IP addresses must be on different subnets.• The usernames are misconfigured.• The passwords must be different for the CHAP authentication.• The clock rate must be 56000.• The clock rate is configured on the wrong end of the link.• Interface serial 0/0 on Left must connect to interface serial 0/1 on Right.4. The output of the show interfaces serial 0/0 command for a frame-relay connection indicates that the serial line is up but the line protocol is down. What are possible causes for this? (Choose two.)• There is an LMI-type mismatch between the Frame Relay switch and the router.• There is no clock present on the serial interface.• The interface is shut down.• RARP is not functioning on the router.• The cable is disconnected.5. Which statements are correct about the point in the network where the responsibility of the service provider ends? (Choose three.)• The International point is on the customer side of the network terminating unit(NTU).• The United States point is at the interface of the customer-provided equipment and the local loop.• The responsibility for this point is controlled by IANA.• The point is called the demarcation point.• The point is typically located at the service provider’s central office.• The point is located between the customer’s local area networks.6. While prototyping an internetwork in the corporate lab, a network administrator is testing a serial link between serial 0/0 interfaces on two routers. The labels on the serial cable ends have been damaged and are unreadable. What command can be issued to determine which router is connected to the DCE cable end?• show interfaces serial 0/0• show version• show controllers serial 0/0• show protocols serial 0/0• show status serial 0/07. A network technician determines DHCP clients are not working properly. The clients are receiving IP configuration information from a DHCP server configured on the router but cannot access the Internet. From the output in the graphic, what is the most likely problem?• The DHCP server service is not enabled.• The inside interface for DCHP is not defined.• The DHCP pool is not bound to the interface.• The pool does not have a default router defined for the clients.• All the host addresses have been excluded from the DHCP pool.8. A technician enters the interface serial 0/0.1 multipoint command when configuring a router. What effect will the multipoint keyword have in this configuration? (Choose two.)• Split-horizon issues will need to be resolved for this network if RIP is the routing protocol.• A subinterface will be defined for each PVC.• All the participating interfaces of remote routers will be configured in the same subnet.• A single DLCI will be used to define all the PVCs to the remote routers.• An IP address will need to be configured on the main interface.9. When configuring a Frame Relay connection, when should a static Frame Relay map be used? (Choose two.)• when the remote router is a non-Cisco router• whe n the remote router does not support Inverse ARP• when the local router is using IOS Release 11.1 or earlier• when broadcast traffic and multicast traffic over the PVC must be controlled• when globally significant rather than locally significant DLCIs a re being used10. Which router command would be used to associate a Layer 2 address with the corresponding Layer 3 address in the internetwork in the diagram?• RouterA(config-if)#frame-relay pvc 100 192.168.15.2• RouterA(config-if)#dialer-map ip 192.168.15.1 100 broadcast• RouterA(config-if)#frame-relay map ip 192.168.15.2 100 broadcast• RouterA (config-if)#dialer-map 192.168.15.1 101 serial 0 broadcast• RouterA (config-if)#frame-relay dlci 101 192.168.15.1 broadcast• RouterA (config-if)#dialer-map 192.168.15.1 inverse-arp broadcast11. Which of the following ISDN protocols is responsible for call setup and call teardown?• ITU-T Q.921• ITU-T Q.931• ITU-T I.430• ITU-T I.43112. What are two ways to resolve split-horizon issues in a Frame Relay network? (Choose two.)• create a full-mesh topology• disable Inverse ARP• use point-to-point subinterfaces• use multipoint subinterfaces• remove the broadcast keyword from the frame-relay map command13. What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco 806 broadband router?• defines which addresses are allowed out of the router• defines which addresses are allowed into the router• defines which addresses can be translated• defines which address es are assigned to a NAT pool14. A system administrator is unable to ping the Serial0/0 interface of RouterB from RouterA. During the troubleshooting process, the following facts are established:- IP addressing and subnet masks are correct.- RouterA is a Cisco router and RouterB is a router from another vendor.- RouterA is configured with the default encapsulation.- The serial interfaces on both routers are up.- The protocol is down on the serial interfaces of both routers.What should the administrator do to solve the problem?• Add a clock rate on RouterA.• Enable the serial interface on RouterB.• Change the encapsulation on both routers to PPP.• Connect the serial cable to the correct interface on RouterB.• Use the correct serial cable to attach the CSU/DSU to RouterB.15. An ISDN circuit from a branch office is remaining connected to the regional office. A network administrator determines a user has initiated a continuous ping from a desktop computer to the regional office. Which configuration change would allow the ISDN circuit to disconnect during any attempts to ping, while otherwise functioning properly?• change DDR from legacy to dialer profiles• remove the dialer list statement from the configuration• change the dialer list to exclude IC MP as interesting• disable inverse ARP16. Below is a list of DDR steps. Which of the following identifies the proper order of DDR?1 - dial number is looked up2 - interesting traffic triggers DDR3 - route to destination is determined4 - call is made• 1,2,3,4• 1,3,2,4• 2,3,1,4• 2,1,3,4• 3,2,1,4• 3,1,2,417. Which protocol should be chosen to support WAN connectivity in a multi-vendor system and provide strong security through authentication?• NAT with DHCP• Frame Relay• HDLC with encryption• H DLC with CHAP• PPP with PAP• PPP with CHAP18. Which of the following are valid steps for a basic ISDN BRI configuration? (Choose two.)• create subinterfaces• define the LMI type• set the SPIDs if required by the ISDN switch• set the interface DLCI• set the switch type• specify the encapsulation as either Cisco or IETF19. A branch office reports excessive connect time charges for an ISDN circuit used to connect to the regional office. Upon investigation of this issue, it is discovered that when an ISDN connection is initiated to the regional office it remains connected for an excessive amount of time. Which of the following configuration changes could be made to DDR on the router to reduce these connect time charges?• use PPP multilink• lower idle timer setting• use CHAP authentication• change DDR from legacy to dialer profiles20. A network administrator is having difficulty in establishing a serial link between a Cisco router and a router from another vendor. Both routers are configured for HDLC encapsulation. Which statements are true regarding this configuration? (Choose two.)• The Cisco HDLC frame uses a proprietary “Type” field that may not be compatible with equipment of other vendors.• HDLC requires a clock rate to be configured on the r outers at both ends of the serial link.• PPP encapsulation is recommended for serial links between equipment from multiple vendors.• Usernames must be configured at both ends of the HDLC serial link.• The HDLC vendor type must be enabled on the Cisco ro uter.• There is a mismatch in the HDLC authentication password configurations.21. Given the partial router configuration in the graphic, why does the workstation with the IP address 192.168.1.153/28 fail to access the Internet? (Choose two.)• The NAT in side interfaces are not configured properly.• The NAT outside interface is not configured properly.• The router is not properly configured to use the access control list for NAT.• The NAT pool is not properly configured to use routable outside addresses.• The access control list does not include the IP address 192.168.1.153/28 to access the Internet.22. The serial PPP link between the Left and Right routers is configured as shown in the diagram. Which configuration issue will prevent IP traffic from crossing this link?• The passwords must be different for the CHAP authentication.• The usernames are misconfigured.• The clock rate must be 56000.• The clock rate is configured on the wrong end of the link.• The IP addresses must be on the same subnet.• Interface serial 0/0 on Left must connect to interface serial 0/1 on Right.23. What causes a DDR call to be placed?• dial string• DLCI• idle time out• interesting traffic• PVC24. Which two layers of the OSI model are described by WAN standards?• Application Layer, Physical Layer• Data Link Layer, Physical Layer• Data Link Layer, Transport Layer• Physical Layer, Network Layer25. A technician is testing RouterA in the graphic. What is the condition of the circuit?• The routers are configured fo r different encapsulations.• The clock rate is not properly configured on the routers.• The circuit from WAN provider has failed.• Authentication is not properly configured on the routers.• The circuit is functioning properly.26. A network administrator must provide WAN connectivity between a central office and three remote sites: Orlando, Atlanta, and Phoenix. The Orlando and Atlanta remote offices receive sales orders and transmit shipping confirmations to the Central office consistently throughout the day. The Phoenix remote office consists of one salesperson traveling through the southwest territory. The salesperson occasionally needs to connect to the Central office for e-mail access. How should the networkadministrator connect the remote sites to the Central office? (Choose two.)• Connect to the Atlanta and Orlando remote offices with Frame Relay connections.• Connect to the Atlanta and Orlando remote offices with ISDN connections.• Connect to the Atlanta and Orlando re mote offices with POTS dial-up connections.• Connect to the Phoenix remote office with a Frame Relay connection.• Connect to the Phoenix remote office with a POTS dial-up connection.27. When a Frame Relay switch detects an excessive buildup of frames in its queue, which of the following may occur? (Choose two.)• Frames with the DE bit set are dropped from the switch queue.• Frames with the FECN and BECN bits set are dropped from the switch queue.• Frames in excess of the CIR are not accepted by the sw itch.• The switch sets the FECN bit on all frames it places on the congested link and sets the BECN bit on all frames it receives on the congested link.• The switch sets the FECN bit on all frames it receives on the congested link and sets the BECN bit o n all frames it places on the congested link.28. A system administrator is troubleshooting a connectivity issue between two routers in a new installation. The administrator enters the debug ppp authentication command on the WHSE router. The graphic shows a part of the output received. From this output, what is the most likely cause of this connectivity issue?• There is not a route to the remote router.• The ISDN circuit on the remote router has failed.• The username/password was not properly configured on the WHSE router.• The remote router has a different authentication protocol configured.29. What does the output of the show frame-relay map command shown below represent? (Choose two.) • Serial 0 (up): ip 172.30.151.4 dlci 122, dynamic, broadcast, sta tus defined, active• 172.30.151.4 represents the IP address of the remote router.• 172.30.151.4 represents the IP address of the local serial interface.• DLCI 122 represents the interface of the remote router.• broadcast indicates that a dynamic routin g protocol such as RIP v1 can send packets across this PVC. • dynamic indicates that a dynamic routing protocol is enabled for this connection.• active indicates that the ARP process is working.30. What does the status inactive indicate in the output of the show frame-relay pvc command?• The DLCI is programmed in the switch but is not usable.• The DLCI was formerly programmed in the switch but is no longer there.• The DLCI is usable but has little activity.• The DLCI has been renamed for that PVC.31. Which of the following IP addresses are defined by RFC 1918 as private addresses? (Choose three.) • 192.168.146.0/22• 172.10.25.0/16• 172.31.0.0/16• 20.0.0.0/8• 10.172.92.8/2932. After configuring a dialup ISDN circuit, a network associate begins testing the dialup connection. When attempting to ping a host on the remote network, the local router does not attempt to dial the remote access server. Which of the following are possible errors in this configuration? (Choose three.) • PPP authentication is not properly configured.• No dialer map is configured.• The ISDN circuit connected to the remote access server is busy.• No interesting traffic is defined.• No route is determined to the remote network.• A wrong number is configured in the dial string.33. Two routers are connected through a Frame Relay, point-to-point PVC. The remote router is from a vendor other than Cisco. Which interface command is required to configure the link between the Cisco router and the other router?• frame-relay pvc multipoint• frame-relay pvc point-to-point• encapsulation frame-relay cisco• encapsulation frame-relay ietf• frame-relay lmi-type ansi34. Which circuit-switched WAN technology is often used to provide a backup for a leased line and additional capacity during peak usage times?• X.25• DSL• ISDN• cable modem35. After the ISDN BRI interface is configured, which command can be used to verify that the router is communicating correctly with the ISDN switch?• show dialer• show isdn status• show interfaces b ri0/0:1• show interfaces serial0/0.136. A system administrator needs to configure the regional office with ISDN for DDR connections to three remote sites. Each remote site requires different IP subnets, different encapsulations, and different authentication methods. The sites will not be connected at the same time. The company would like to accomplish this in the most cost effective manner. What method can the system administrator use to accomplish this task using the fewest B channels?• Install and conf igure a PRI.• Install and configure a BRI interface with separate SPIDs for each remote site.• Install and configure a BRI with multiple switch types in global configuration.• Install and configure a BRI using dialer profiles.• Install and configure a separate BRI for each remote site.37. A system administrator must provide Internet connectivity for ten hosts in a small remote office. The ISP has assigned two public IP addresses to this remote office. How can the system administrator configure the router to provide Internet access to all ten users at the same time?• Configure static NAT for all ten users.• Configure dynamic NAT for ten users.• Configure dynamic NAT with PAT.• Configure DHCP and static NAT.• What the administrator wants to do cannot be done.38. Which of the following are characteristics of Frame Relay? (Choose two.)• circuit-switched• connection oriented• OSI Layer 3• packet-switched• reliable39. Which of the following is the order for the three phases of establishing a PPP serial link with authentication?• authentication, link-establishment, network layer protocols• authentication, network layer protocols, link-establishment• network layer protocols, link-establishment, authentication• network layer protocols, authenticati on, link-establishment• link-establishment, authentication, network layer protocols• link-establishment, network layer protocols, authentication。

CCNA4在线答案第2章

1 制作商务案例的目的是什么？AA.用于证明实施技术改进所需的资金投入的合理性B.用于为之前在RFP 中完成的工作提供例子。

C.用于定义网络的技术要求D.用于定义时间表和关键里程碑2 开发网络设计时，为什么必须排列业务目标的优先顺序？DA.为确保首先实现最廉价的技术B.为简化新安装网络的配置、管理和监控工作C.为预测变化和业务增长所带来的影响D.为抓住有助于业务成功的最佳机遇3 Cisco 生命周期服务的哪个阶段会执行网络基线？EA.准备阶段B.规划阶段C.设计阶段D.实施阶段E.运行阶段4 在网络管理体系结构中，哪一项是对管理代理的准确描述？DA.存储网络性能参数的标准数据库B.管理站与被管理设备之间采用的通信协议C.管理员用于监控和配置网络设备的、运行管理应用程序的主机D.在受管设备上运行的软件，用于收集网络信息并使管理站可管理该设备5 Cisco 生命周期服务的哪个阶段会采取主动管理以确认并解决问题，避免组织受到影响？FA.准备阶段B.规划阶段C.设计阶段D.实施阶段E.运行阶段F.优化阶段6 系统级验收测试的目的是什么？CA.为新设计的网络开发安装计划B.在新安装的网络上培训最终用户和支持人员C.检查新安装的网络是否符合业务目标和设计要求D.用于证明实施技术改进所需的资金投入的合理性7 在网络设计中使用自上而下的方法替代自下而上的方法有哪两项优点？（选择两项）A.DA.符合组织要求B.可快速对设计要求作出反应C.减少网络设计的前期准备时间D.从应用程序和网络解决方案的角度明确设计目标E.可根据以往经验选用设备和技术以实现设计8 下列哪项业务制约条件可能影响公司的W AN 设计？DA.公司政策中关于LAN 设备上特定操作系统的规定B.当前在用户设备上实施的监控协议C.实施过程中最终用户无法使用网络D.公司政策因合作关系而要求使用特定厂商的网络设备9 以下哪个组件安装在由SNMP 管理的网络设备上？AA.管理代理B.管理站C.网络管理协议D.管理信息库(MIB)10 SNMP 有何用途？AA.帮助在设备与NMS 之间交换信息B.监视和控制网络中的IP 地址分配C.向监控工作站报告用户登录情况D.检验网络中的流量并记录所有活动11 组织在发出征求建议书(RFP) 或征求报价书(RFQ) 前，通常完成了Cisco 生命周期服务策略的哪个阶段？AA.准备阶段B.规划阶段C.设计阶段D.实施阶段E.运行阶段F.优化阶段12 一家承包公司的网络工程师接到一个会议通知，内容是与潜在客户举行的投标前会谈。