Ch. 19 Network Troubleshooting

Question 1

What is step 3 of the seven-step troubleshooting model?

Answer 1

Test the theory to determine cause

Question 2

What is step 7 of the seven-step troubleshooting model?

Answer 2

Document findings, actions, and outcomes

Question 3

How is crosstalk minimized in twisted-pair cabling?

Answer 3

Network designers minimize crosstalk inside network cables by twisting the wire pairs
together, putting them at a 90-degree angle to each other.

Question 4

If you plug a host into a switch port and the user cannot get to the server or other services
they need to access despite a working link light, what could the problem be?

Answer 4

The port has the wrong VLAN assignment.

Question 5

What is it called when a cable has two wires of a twisted pair connected to two wires from
a different pair?

Answer 5

Split pairs

Question 6

When a signal moves through any medium, the medium itself will degrade the signal. What
is this called?

Answer 6

Attenuation

Question 7

What is step 4 of the seven-step troubleshooting model?

Answer 7

Establish a plan of action to resolve the problem and identify potential effects

Question 8

What is step 5 of the seven-step troubleshooting model?

Answer 8

Implement the solution or escalate as necessary

Question 9

What are some of the problems that, if determined, should be escalated?

Answer 9

Switching loops, routing loops, routing problems, Proxy ARP, broadcast storms

Question 10

What cable issues should you know and understand for network troubleshooting?

Answer 10

Crosstalk, attenuation, collisions, shorts, open impedance mismatch, interference

Question 11

Which of the following are not steps in the Network+ troubleshooting model? (Choose all
that apply.)
A. Reboot the servers.
B. Identify the problem.
C. Test the theory to determine the cause.
D. Implement the solution or escalate as necessary.
E. Document findings, actions, and outcomes.
F. Reboot all the routers

Answer 11

A, F. Rebooting servers and routers are not part of the troubleshooting model.

Question 12

You have a user who cannot connect to the network. What is the first thing you could
check to determine the source of the problem?
A. Workstation configuration
B. Connectivity
C. Patch cable
D. Server configuration

Answer 12

B. You need to check basic connectivity. The link light indicates that the network card is
making a basic-level connection to the rest of the network. It is a very easy item to check,
and if the link light is not lit, it is usually a very simple fix (like plugging in an unplugged
cable).

Question 13

When wireless users complain that they are losing their connection to applications during a
session, what is the source of the problem?
A. Incorrect SSID
B. Latency
C. Incorrect encryption
D. MAC address filter

Answer 13

B. When wireless users complain that the network is slow (latency) or that they are losing
their connection to applications during a session, it is usually latency arising from a
capacity issue.

Question 14

Several users can’t log in to the server. Which action would help you to narrow the problem
down to the workstations, network, or server?
A. Run tracert from a workstation.
B. Check the server console for user connections.
C. Run netstat on all workstations.
D. Check the network diagnostics.

Answer 14

B. Although all of these are good tests for network connectivity, checking the server
console for user connections will tell you whether other users are able to log into the server.
If they can, the problem is most likely related to one of those users’ workstations. If they
can’t, the problem is either the server or network connection. This helps narrow down the
problem.

Question 15

A user can’t log in to the network. She can’t even connect to the Internet over the LAN.
Other users in the same area aren’t experiencing any problems. You attempt to log in as
this user from your workstation with her username and password and don’t experience
any problems. However, you cannot log in with either her username or yours from her
workstation. What is a likely cause of the problem?
A. Insufficient rights to access the server
B. A bad patch cable
C. Server down
D. Wrong username and password

Answer 15

B. Because of all the tests given and their results, you can narrow the problem down to
the network connectivity of that workstation. And because no other users in her area are
having the same problem, it can’t be the hub or server. You can log in as the user from
your workstation, so you know it isn’t a rights issue or username/password issue. The only
possible answer listed is a bad patch cable.

Question 16

A user is experiencing problems logging in to a Unix server. He can connect to the Internet
over the LAN. Other users in the same area aren’t experiencing any problems. You attempt
logging in as this user from your workstation with his username and password and don’t
experience any problems. However, you cannot log in with either his username or yours
from his workstation. What is a likely cause of the problem?
A. The Caps Lock key is pressed.
B. The network hub is malfunctioning.
C. You have a downed server.
D. You have a jabbering NIC.

Answer 16

A. Because other users in the same area aren’t having a problem, it can’t be a downed
server, network hub, or jabbering NIC. And because both you and the user can’t log in,
more than likely it’s a problem specific to that workstation. The only one that would affect
your ability to log in from that station is the Caps Lock key being pressed. That will cause
the password to be in all uppercase (which most server operating systems treat as a different
password), and thus it will probably be rejected.

Question 17

You receive a call from a user who is having issues connecting to a new VPN. Which is the
first step you should take?
A. Find out what has changed.
B. Reboot the workstation.
C. Document the solution.
D. Identify the symptoms and potential causes.

Answer 17

D. Since this is a new connection, you need to start by troubleshooting and identify the
symptoms and potential causes.

Question 18

A workstation presents an error message to a user. The message states that a duplicate
IP address has been detected on the network. After establishing what has changed in the
network, what should be the next step using the standard troubleshooting model?
A. Test the result.
B. Select the most probable cause.
C. Create an action plan.
D. Identify the results and effects of the solution.

Answer 18

B. According to the Network+ troubleshooting model, the next step would be step 2, establishing the most probable cause.

Question 19

You have gathered information on a network issue and determined the affected areas of the
network. What is your next step in resolving this issue?
A. You should implement the best solution for the issue.
B. You should test the best solution for the issue.
C. You should check to see if there have been any recent changes to this affected part of
the network.
D. You should consider any negative impact to the network that might be caused by a
solution.

Answer 19

C. After determining the affected area, you need to find out if any changes have taken
place.

Question 20

A user calls you, reporting a problem logging in to the corporate intranet. You can access
the website without problems using the user’s username and password. At your request, the
user has tried logging in from other workstations but has been unsuccessful. What is the
most likely cause of the problem?
A. The user is logging in incorrectly.
B. The network is down.
C. The intranet server is locked up.
D. The server is not routing packets correctly to that user’s workstation.

Answer 20

A. Because the user can’t log in correctly from any machine, more than likely he is using
the wrong procedure for logging in. Because no one else is having that problem (including
yourself), the problem must be related to that user.

Question 21

You have just implemented a solution and you want to celebrate your success. But what
should you do next before you start your celebration?
A. Gather more information about the issue.
B. Document the issue and the solution that was implemented.
C. Test the solution and identify other effects it may have.
D. Escalate the issue.

Answer 21

C. After you have implemented a solution, you need to test if the solution works and
identify other effects it may have.

Question 22

You can ping the local router and web server that a local user is trying to reach, but you
cannot reach the web page that resides on that server. From step 2 of the troubleshooting
model, what is a possible problem that would lead to this situation?
A. Your network cable is unplugged.
B. There is a problem with your browser.
C. Your NIC has failed.
D. The web server is unplugged

Answer 22

B. Because you cannot reach the web page that resides on the server, the problem is most
likely related to your browser.

Question 23

When troubleshooting an obscure network problem, what physical conditions should be
reviewed to make sure the network device is operating correctly? (Choose all that apply.)
A. Excessive heat
B. Low/excessive humidity
C. ESD problems
D. None of the above

Answer 23

A, B, C. From a design standpoint, the physical environment for a server should be
optimized for items such as placement, temperature, and humidity. When troubleshooting,
don’t forget to check the physical conditions under which the network device is operating.
Check for problems such as those mentioned here as well as EMI/RFI problems, power
problems, and unplugged cables.

Question 24

Which of the following is not a basic physical issue that can occur on a network when a
user is connected via cable?
A. Crosstalk
B. Shorts
C. Open impedance mismatch
D. DNS configurations

Answer 24

D. Because most of today’s networks still consist of large amounts of copper cable,
networks can suffer from the physical issues that have plagued all networks since the
very beginning of networking (and the answers here are not a complete list). Newer
technologies and protocols have lessened these issues but have not resolved them
completely.

Question 25

You are troubleshooting a LAN switch and have identified the symptoms. What is the next
step you should take?
A. Escalate the issue.
B. Create an action plan.
C. Implement the solution.
D. Determine the scope of the problem.

Answer 25

A. Once you have determined that the switch or the configuration of the switch is the
problem, you need to escalate the issue.

Question 26

A user calls you, complaining that he can’t access the corporate intranet web server. You try
the same address, and you receive a Host Not Found error. Several minutes later, another
user reports the same problem. You can still send email and transfer files to another server.
What is the most likely cause of the problem?
A. The hub is unplugged.
B. The server is not routing protocols to your workstation.
C. The user’s workstation is not connected to the network.
D. The web server is down

Answer 26

D. Because other people are experiencing the problem, most likely it is either network or
server related. Because you can transfer files to and from another server, it can’t be the
network. Thus, the problem is related to the web server.

Question 27

You have implemented and tested a solution and identified any other effects the solution
may have. What is your next step?
A. Create an action plan.
B. Close the case and head home for the day.
C. Reboot the Windows server.
D. Document the solution.

Answer 27

D. After investigating the problem thoroughly and successfully testing and resolving an
issue, you need to document the solution.

Question 28

Users are reporting that they can access the Internet but not the internal company website.
Which of the following is the most likely problem?
A. The DNS entry for the server is non-authoritative.
B. The intranet server is down.
C. The DNS address handed out by DHCP is incorrect.
D. The default gateway is incorrect.

Answer 28

B. Since users can get to the Internet, this means the DNS server is working and they have
the correct default gateway. The intranet server is probably down.

Question 29

Several users have complained about the server’s poor performance as of late. You know
that the memory installed in the server is sufficient. What could you use to determine the
source of the problem?
A. Server’s NIC link light
B. Protocol analyzer
C. Performance-monitoring tools
D. Server’s system log file

Answer 29

C. Performance-monitoring tools can give you an idea of how busy the server and the rest
of the network are. These tools use graphs to indicate how much traffic is going through the
server.

Question 30

You lose power to your computer room and the switches in your network do not come back
up when everything is brought online. After you have identified the affected areas, established the cause, and escalated this problem, what do you do next?
A. Start to implement a solution to get those users back online ASAP.
B. Create an action plan and solution.
C. Meet with the emergency response team to determine the next step.
D. Copy all the working routers’ configurations to the nonworking switches.

Answer 30

C. Once you escalate the problem, you are done with the seven-step model. Meet with the
escalation team to determine the next step.