1.
You work as a network administrator. Your network is medium-sized and consists of a mixture of different platform computers. The network is split into multiple subnets located across a large geographical area. IEEE 802.11g Wireless Access Points are found in more than half of the subnets. You receive reports that one of the subnets has experienced a lot of downtime. You are sent to the branch office with the problematic network to conduct on-site troubleshooting. You soon notice that the downtime only affects wireless users and the downtime lasts approximately an hour around midday every day. Which of the following would be an appropriate action to address this problem?
Correct Answer
B. Eliminate any sources of Radio Frequency Interference (RFI) around the WAP
Explanation
802.11g uses the 2.4 GHz range which is also used by appliances such as microwaves. The connectivity problem occurs at around lunch time, which seems to indicate that the increased use of microwaves at around this time is causing RFI (Radio Frequency Interference). We should thus attempt to eliminate this RFI.
2.
You work as an administrator on a network that consists of two 100BASE-TX hubs - Hub CKa and Hub CKb. A 3 meter (9.84 feet) straight-through patch cable connects the two hubs. You receive reports about some problems with the network connectivity for some hosts, and further investigations reveals that no users on Hub CKa are able to communicate with the users on Hub CKb. What can you do to resolve the problem?
Correct Answer
C. Replace the patch cable that connects Hub A to Hub B with a crossover patch cable
Explanation
The Ethernet connections on the two hubs are physically and electronically the same medium dependent interface-crossover (MDI-X) port, therefore, you need a crossover cable to connect the two hubs, and not a straight-though cable.
3.
You work as a network technician. You are asked to troubleshoot some problems with slow Internet connections from specific hosts. You suspect that the slowness of the network is caused by retransmits because of dropped packets so you use a specific tool to capture network packets. When you are about to analyze the packets you notice that you have only captured broadcast packets and packets from your own computer. Why?
Correct Answer
B. You are connected to a switch when trying to capture packets
Explanation
A switch builds a table over MAC addresses so a packet will only be transmitted to the port with the receiving machine. Hubs to transmit packets out on all ports except the port that received the packet. In order to sniff packets on a switched net you need to put the switches MAC address table out of order by for example flooding it which makes the switch to act as a hub for a short while.
4.
You are working as a senior network technician. A trainee that is asked to configure a couple of new laptops for wireless connectivity wants to know what happens if the wrong WEP (Wired Equivalent Privacy) key is entered into a wireless device. What would your answer be?
Correct Answer
C. The network is not accessible
Explanation
WEP requires that both the wireless computer and the WAP (wireless access point) be configured with the same encryption key in order for the two to communicate. If one of the two has the wrong WEP key, communication will not be possible and the network will not be accessible.
5.
What is the first step in resolving a network problem?
Correct Answer
D. Identify the symptoms
Explanation
The first step in troubleshooting is to identify the problem by estabishing the symptoms. This can be done by asking some questions to begin to clarify exactly what is happening.
6.
You are a network administrator. Some users are complaining about connectivity problems. You have identified the symptoms and the affected area. What is your next step?
Correct Answer
B. Identify what has changed
Explanation
Once you have identified the affected area, you should determine if anything has been changed in the affected area. This will help you identify the probable cause.
7.
You are a network technician. You have just completed the successful solution of connectivity problem on a workstation. What should you do next?
Correct Answer
C. Document the solution
Explanation
Once you have resolved a problem, you should document the solution. This will help you resolve similar problems in the future.
8.
The first step in resolving a network problem is to _______.
Correct Answer
D. Identify the symptoms
Explanation
The first step in troubleshooting is to identify the problem by estabishing the symptoms. This can be done by asking some questions to begin to clarify exactly what is happening.
9.
What is the final step in solving a network problem?
Correct Answer
C. Document the solution
Explanation
Once you have resolved a problem, you must document the solution. This will help you resolve similar problems in the future.
10.
You are a network technician. You are addressing a network problem and have established that nothing was changed. What is your next step?
Correct Answer
A. Select the most probable cause
Explanation
Once you have determined that nothing has been changed in the affected area, you should identify the most probable cause. This will allow you to address the problem systematically by eliminating most probable causes first.
11.
You are troubleshooting a network connectivity problem. You have determined what the most probable cause could be. What should you do next?
Correct Answer
C. Implement a solution
Explanation
Once you have what the most probable cause is, you can implement an action plan and solution to address the probable cause.
12.
Which of the following follows after implementing a solution?
Correct Answer
D. Test the solution
Explanation
Testing a solution follows after implementing a solution as your solution addresses the most probable cause. Testing will determine whether the most probable cause is in fact the problem.
13.
You are a network assistant. The network technician is troubleshooting a network connectivity problem. He asks you to determine the most probable cause of the problem. Which of the following would you need to do? (Choose all that apply)
Correct Answer(s)
A. Identify the symptoms
B. Identify the affected area
C. Identify what has changed
Explanation
Before you can determine what the most probable cause is, you must first identify the symptoms, narrow the problem down by identifying the affected area, and establish what has changed in the affected area.
14.
You are the network technician. You are troubleshooting a network connectivity problem. Your assistant has determined the most probable cause of the problem. Which of the following would you need to do?
Correct Answer
D. Implement an action plan
Explanation
Implementing an action plan and a solution follows after selecting the most probable cause which follows after identifying what has changed.
15.
The last step in resolving a network problem is to ______.
Correct Answer
C. Document the solution
Explanation
Once you have resolved a problem, you must document the solution. This will help you resolve similar problems in the future.
16.
After implementing a solution you must ______.
Correct Answer
D. Test the solution
Explanation
Testing a solution follows after implementing a solution as your solution addresses the most probable cause. Testing will determine whether the most probable cause is in fact the problem.
17.
After identifying the symptoms of a problem, the next step is to ______.
Correct Answer
D. Identify the affected area
Explanation
Once you have identified the symptoms, you must determine which part of the network is affected by the same symptoms.
18.
After identifying the area affected by a problem, the next step is to ______.
Correct Answer
B. Identify what has changed
Explanation
Once you have identified the affected area, you should determine if anything has been changed in the affected area. This will help you identify the probable causes.
19.
You are working as a technician. A Mac OS X 10.3 user has requested some assistance with a network connectivity issue that he is experiencing. The Mac OS uses Kerberos to access a service provided by a Mac OS X server 10.3 but the user experiences an authentication failure. Which of the following steps might resolve the issue?
Correct Answer
B. Synchronize all Kerberos principal's clocks using a network time server
Explanation
The security of the protocol relies heavily on timestamps and lifespans as reliable indicators of the freshness of a communication.
20.
You work as a web master. You use a Linux machine to host the website. Recently users have been complaining that they receive a forbidden error message when they try to visit the web site. You log onto the Linux server and navigate to the directory where the web site pages are stored. What should you do next?
Correct Answer
D. Change the permissions of the directory
Explanation
Modifying the permissions on the web page files makes the most sense.
21.
You work as a network technician. You are asked to check out the computer lab as users have complained that they are unable to connect to the network from one of the machines. The lab consist of three identical desktop computers. You check the network interface card in the problematic computer and find that neither the link light nor the activity light is illuminated. You swap the network cable with a cable that is known to be operational, but the lights still do not illuminate on the NIC or the corresponding port on the switch. What would be your next troubleshooting step?
Correct Answer
C. Change ports on the switch
Explanation
Trying a different port would help rule out a faulty port on the switch.