CCNA 4 Chapter 8 Exam Answers v5.0.3 & v6.0

1. When should a network performance baseline be measured?after normal work hours to reduce possible interruptions
   during normal work hours of an organization*
   when a denial of service attack to the network is detected and blocked
   immediately after the main network devices restarted
   
   
   The purpose of a network performance baseline is to record the characteristics of a network during normal operations. This can be used as a standard to determine when a network is performing abnormally. Measurements that are performed during particular circumstances (such as main network device restart or after working hours) will result in an inaccurate set of characteristics for the purpose of a baseline. A DoS attack might cause abnormal network performance, but once it is blocked, network performance should return to normal, so there is no immediate need to measure performance in order to establish a baseline.
2. What is a purpose of establishing a network baseline?It provides a statistical average for network performance.
   It creates a point of reference for future network evaluations.*
   It manages the performance of network devices.
   It checks the security configuration of network devices.
   
   
   A baseline is used to establish normal network or system performance. It can be used to compare with future network or system performances in order to detect abnormal situations.
3. Which three pieces of information are typically recorded in a logical topology diagram? (Choose three.)device models and manufacturers
   device locations
   cable specifications
   static routes*
   routing protocols*
   IP address and prefix lengths*
   
   
   There are two types of network topology diagrams: physical topology diagrams and logical topology diagrams. Logical topology diagrams show how devices are logically connected and how data moves through the network. Logical topology diagrams include information such as IP addresses, routing protocols, and static routes.
4. In which step of gathering symptoms does the network engineer determine if the problem is at the core, distribution, or access layer of the network?Determine the symptoms.
   Narrow the scope.*
   Determine ownership.
   Gather information.
   Document the symptoms.
   
   
   In the “narrow the scope” step of gathering symptoms, a network engineer will determine if the network problem is at the core, distribution, or access layer of the network. Once this step is complete and the layer is identified, the network engineer can determine which pieces of equipment are the most likely cause.
5. A team of engineers has identified a solution to a significant network problem. The proposed solution is likely to affect critical network infrastructure components. What should the team follow while implementing the solution to avoid interfering with other processes and infrastructure?syslog messages and reports
   one of the layered troubleshooting approaches
   knowledge base guidelines
   change-control procedures*
   
   
   Change-control procedures should be established and applied for each stage to ensure a consistent approach to implementing the solutions, and to enable changes to be rolled back if they cause other unforeseen problems.
6. Refer to the exhibit. What action occurs at stage 3 of the general troubleshooting process?
   
   Document symptoms.
   Question end users.
   Narrow the scope.
   Correct the problem.*
   There are three stages in the general troubleshooting process:
   Gather symptoms
   Isolate the problem
   Correct the problem
   If the problem is not corrected, the administrator documents the attempted solution, removes any changes made, and returns to gathering symptoms.
7. After which step in the network troubleshooting process would one of the layered troubleshooting methods be used?documenting symptoms
   determining ownership
   narrowing the scope
   gathering symptoms from suspect devices*
   
   
   A layered troubleshooting approach (top-down, bottom-up, or divide-and-conquer) is used to gather hardware and software symptoms from the suspect devices.
8. A network technician is troubleshooting an email connection problem. Which question to the end-user will provide clear information to better define the problem?How big are the emails you tried to send?
   What kind of equipment are you using to send emails?
   Is your email working now?
   When did you first notice your email problem?*
   
   
   To efficiently establish exactly when the user first experienced email problems, an open-ended question should be asked so that the user can state the day and time that the problem was first noticed. Closed questions only require a yes or no answer which will require further questions to determine the actual time of the problem.
9. A network engineer is troubleshooting a network problem and can successfully ping between two devices. However, Telnet between the same two devices does not work. Which OSI layers should the administrator investigate next?from the network layer to the physical layer
   all of the layers
   only the network layer
   from the network layer to the application layer*
   
   
   A successful ping indicates that everything is working on the physical, data link, and network layer. All of the other layers should be investigated.
10. A network administrator is having issues with a newly installed network not appearing in other routers. At which layer of the OSI model is the network administrator going to start the troubleshooting process when using a top-down approach?internet
    application
    network*
    session
    transport
    
    
    Routing is a Layer 3 process. The network layer is another name for Layer 3. The top-down method of troubleshooting typically starts at the application layer, but when a problem is definitely a routing problem, there is no need for troubleshooting to be performed at the higher levels. The problem can only be a Layer 1, 2, or 3 problem.
11. Which troubleshooting method begins by examining cable connections and wiring issues?top-down
    divide-and-conquer
    substitution
    bottom-up*
    
    
    In troubleshooting with the bottom-up method, a technician would start with the physical components of the network and move up through the layers of the OSI model until the cause of the problem is identified.
12. Refer to the exhibit. On the basis of the information presented, which two IP SLA related statements are true? (Choose two.)
    IP SLA 99 will run forever unless explicitly disabled.*
    IP SLA 99 is measuring jitter.
    IP SLA 99 is configured with the type dns target-addr 192.168.2.1 command.
    IP SLA 99 is sending echo requests from IP address 192.168.2.1.
    IP SLA 99 is scheduled to begin in 2 hours.
    IP SLA 99 is sending echo requests every 10 seconds.*
    
    
    From the output, the IP SLA is configured to perform icmp-echo, the target device is 192.168.2.1, and the icmp-echo requests are sent every 10 seconds. “Start Time already passed” indicates that the operation has started. The “Life” parameter indicates that the setting is “Forever”.
13. A company is setting up a web site with SSL technology to protect the authentication credentials required to access the web site. A network engineer needs to verify that the setup is correct and that the authentication is indeed encrypted. Which tool should be used?baselining tool
    cable analyzer
    protocol analyzer*
    fault-management tool
    
    
    To verify that the authentication is indeed encrypted, the authentication process needs to be captured and investigated, which can be accomplished through a protocol analyzer, such as Wireshark. A baselining tool is used for automating the network documentation and baselining process. A fault-management tool is used to manage the fault tolerance of network devices . A cable analyzer is used to test and certify copper and fiber cables for different services and standards.
14. Which category of software troubleshooting tools provides device-level monitoring, configuration, and fault-management?host-based protocol analyzers
    baselining tools
    knowledge bases
    network management system tools*
    
    
    Network management system (NMS) tools include device-level monitoring, configuration, and fault-management tools. Knowledge bases are online repositories of experience-based information. Baselining tools perform tasks of network baselining documentation, network diagram drawings, and network performance statistics establishment. Host-based protocol analyzers capture and decode the various protocol layers in a recorded frame and present the information in a relatively easy to use format.
15. Which two specialized troubleshooting tools can monitor the amount of traffic that passes through a switch? (Choose two.)DTX cable analyzer
    TDR
    digital multimeter
    portable network analyzer*
    NAM*
    
    
    Network analysis modules and portable network analyzers such as the Fluke OptiView can monitor network traffic to investigate the amount of data going through switch ports. TDRs, DMMs, and DTX cable analyzers are used to investigate physical media errors and lengths.
16. Which number represents the most severe level of syslog logging?0*
    1
    6
    7
    
    
    Syslog levels are numbered 0 through 7, with 0 being the most severe and 7 being the least severe.
17. A user in a large office calls technical support to complain that a PC has suddenly lost connectivity to the network. The technician asks the caller to talk to nearby users to see if other machines are affected. The caller reports that several immediate neighbors in the same department have a similar problem and that they cannot ping each other. Those who are seated in other departments have connectivity. What should the technician check as the first step in troubleshooting the issue?the power outlet to the PC that is used by the caller
    the cable connection between a PC and a network outlet that is used by a neighbor
    the cable that connects the PC of the caller to the network jack
    the status of the departmental workgroup switch in the wiring closet*
    the trunks between switches in the wiring closet
18. A user reports that after an OS patch of the networking subsystem has been applied to a workstation, it performs very slowly when connecting to network resources. A network technician tests the link with a cable analyzer and notices that the workstation sends an excessive number of frames smaller than 64 bytes and also other meaningless frames. What is the possible cause of the problem?corrupted application installation
    cabling faults
    corrupted NIC driver*
    Ethernet signal attenuation
    
    
    The symptom of excessive runt packets and jabber is typically a Layer 1 issue, such as caused by a corrupted NIC driver, which could be the result of a software error during the NIC driver upgrade process. Cable faults would cause intermittent connections, but in this case, the network is not touched and the cable analyzer has detected frame problems, not signal problems. Ethernet signal attenuation is caused by an extended or long cable, but in this case, the cable has not been changed. A NIC driver is part of the operating system, it is not an application.
19. An administrator is troubleshooting an Internet connectivity problem on a router. The output of the show interfaces gigabitethernet 0/0 command reveals higher than normal framing errors on the interface that connects to the Internet. At what layer of the OSI model is the problem likely occurring?Layer 1
    Layer 2*
    Layer 3
    Layer 4
    Layer 7
    
    
    Framing errors are symptoms of problems at the data link layer, Layer 2, of the OSI model.
20. A group of Windows PCs in a new subnet has been added to an Ethernet network. When testing the connectivity, a technician finds that these PCs can access local network resources but not the Internet resources. To troubleshoot the problem, the technician wants to initially confirm the IP address and DNS configurations on the PCs, and also verify connectivity to the local router. Which three Windows CLI commands and utilities will provide the necessary information? (Choose three.)ping*
    arp -a
    netsh interface ipv6 show neighbor
    nslookup*
    tracert
    ipconfig*
    telnet
    
    
    The ipconfig and nslookup commands will provide initial IP address and DNS configuration information to the technicians and determine if DHCP is assigning correct information to the PCs. The ping utility would be used to verify, or not, connectivity to the default gateway (router) using the configured default gateway address, or using the known correct default gateway address if these are found to be different. The arp -a or netsh interface ipv6 show neighbor commands could be used if the problem is then suspected to be an IP address to MAC address mapping issue. The telnet and tracert utilities could be used to determine where the problem was located in the network if the default gateway configuration was found to be correct.
21. Users report that the new web site http://www.company1.biz cannot be accessed. The helpdesk technician checks and verifies that the web site can be accessed with http://www.company1.biz:90. Which layer in the TCP/IP model is involved in troubleshooting this issue?transport*
    application
    network access
    internet
    
    
    The issue is that the new web site is configured with TCP port 90 for HTTP, which is different from the normal TCP port 80. Therefore, this is a transport layer issue.
22. A networked PC is having trouble accessing the Internet, but can print to a local printer and ping other computers in the area. Other computers on the same network are not having any issues. What is the problem?The PC has a missing or incorrect default gateway.*
    The link between the switch to which the PC connects and the default gateway router is down.
    The switch port to which the PC connects has an incorrect VLAN configured.
    The default gateway router does not have a default route.
    
    < div class="message_box success">Since other computers on the same network work properly, the default gateway router has a default route and the link between the workgroup switch and the router works. An incorrectly configured switch port VLAN would not cause these symptoms.