CSIS330 Module 10 - Introduction to Networks Course
- Final Exam.
Study Guide: Questions, Choices, Correct Answers, and Explanations
How to use this guide: Correct answers are highlighted in green. For matching questions, the green cells show the
correct match. Recreated exhibits are included for questions that referenced a graphic.
Question 1
Exhibit:
Refer to the exhibit. Host B on subnet Teachers transmits a packet to host D on subnet Students. Which Layer 2 and
Layer 3 addresses are contained in the PDUs that are transmitted from host B to the router?
Correct Answer choice
Layer 2 destination address = 00-00-0c-94-36-cd
Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.99
Layer 3 source address = 172.16.10.200
Layer 2 destination address = 00-00-0c-94-36-dd
Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.200
Layer 3 source address = 172.16.10.200
Layer 2 destination address = 00-00-0c-94-36-ab
Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.200
Layer 3 source address = 172.16.100.200
Layer 2 destination address = 00-00-0c-94-36-ab
✓ Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.200
Layer 3 source address = 172.16.10.200
Explanation: Because Host D is on a different subnet, Host B sends the frame to the default gateway. The Layer 2
destination is the router Fa0 MAC address, while the Layer 3 destination stays Host D's IP address.
Question 2
What will happen if the default gateway address is incorrectly configured on a host?
, Correct Answer choice
The host cannot communicate with other hosts in the
local network.
A ping from the host to 127.0.0.1 would not be
successful.
The host will have to use ARP to determine the correct
address of the default gateway.
The switch will not forward packets initiated by the host.
The host cannot communicate with hosts in other
✓ networks.
Explanation: A wrong default gateway usually does not stop local communication, but it prevents traffic from being
routed to other networks.
Question 3
Which scenario describes a function provided by the transport layer?
Correct Answer choice
A student has two web browser windows open in
✓ order to access two web sites. The transport layer
ensures the correct web page is delivered to the
correct browser window.
A corporate worker is accessing a web server located on
a corporate network. The transport layer formats the
screen so the web page appears properly no matter what
device is being used to view the web site.
A student is using a classroom VoIP phone to call home.
The unique identifier burned into the phone is a
transport layer address used to contact another network
device on the same network.
A student is playing a short web-based movie with sound.
The movie and sound are encoded within the transport
layer header.
Explanation: The transport layer uses port numbers to keep different application sessions separate.
Question 4
Which two statements describe features of an IPv4 routing table on a router? (Choose two.)
Correct Answer choice
The routing table lists the MAC addresses of each active
interface.
If a default static route is configured in the router, an
✓ entry will be included in the routing table with
source code S.
If there are two or more possible routes to the same
destination, the route associated with the higher metric
value is included in the routing table.
The netstat -r command can be used to display the
routing table of a router.
It stores information about routes derived from the
✓ active router interfaces.
Directly connected interfaces will have two route source
codes in the routing table: C and S.
Explanation: Static routes appear with source code S, and active router interfaces create connected/local routing
information. MAC mappings are stored in ARP tables, not routing tables.
, Question 5
A network administrator needs to keep the user ID, password, and session contents private when establishing remote
CLI connectivity with a switch to manage it. Which access method should be chosen?
Correct Answer choice
Console
AUX
Telnet
✓ SSH
Explanation: SSH encrypts remote management traffic; Telnet sends information in clear text.
Question 6
Which two statements accurately describe an advantage or a disadvantage when deploying NAT for IPv4 in a
network? (Choose two.)
Correct Answer choice
NAT improves packet handling.
NAT provides a solution to slow down the IPv4
✓ address depletion.
NAT introduces problems for some applications that
✓ require end-to-end connectivity.
NAT causes routing tables to include more information.
NAT will impact negatively on switch performance.
NAT adds authentication capability to IPv4.
Explanation: NAT lets many private hosts share fewer public IPv4 addresses, but it can interfere with applications that
require direct end-to-end connectivity.
Question 7
What technique is used with UTP cable to help protect against signal interference from crosstalk?
Correct Answer choice
wrapping a foil shield around the wire pairs
terminating the cable with special grounded connectors
encasing the cables within a flexible plastic sheath
✓ twisting the wires together into pairs
Explanation: UTP means unshielded twisted pair. The twists help cancel interference and reduce crosstalk.
Question 8
Match the header field with the appropriate layer of the OSI model.
Available options: Layer 2, Layer 3, Layer 4
Item / description Correct match
FCS (frame check sequence) Layer 2
802.2 header Layer 2
Destination MAC address Layer 2
Source IP address Layer 3
TTL Layer 3
Destination port number Layer 4
Acknowledgement number Layer 4
Explanation: Layer 2 uses frame and MAC fields, Layer 3 uses IP fields, and Layer 4 uses transport fields such as
ports and TCP acknowledgement numbers.
- Final Exam.
Study Guide: Questions, Choices, Correct Answers, and Explanations
How to use this guide: Correct answers are highlighted in green. For matching questions, the green cells show the
correct match. Recreated exhibits are included for questions that referenced a graphic.
Question 1
Exhibit:
Refer to the exhibit. Host B on subnet Teachers transmits a packet to host D on subnet Students. Which Layer 2 and
Layer 3 addresses are contained in the PDUs that are transmitted from host B to the router?
Correct Answer choice
Layer 2 destination address = 00-00-0c-94-36-cd
Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.99
Layer 3 source address = 172.16.10.200
Layer 2 destination address = 00-00-0c-94-36-dd
Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.200
Layer 3 source address = 172.16.10.200
Layer 2 destination address = 00-00-0c-94-36-ab
Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.200
Layer 3 source address = 172.16.100.200
Layer 2 destination address = 00-00-0c-94-36-ab
✓ Layer 2 source address = 00-00-0c-94-36-bb
Layer 3 destination address = 172.16.20.200
Layer 3 source address = 172.16.10.200
Explanation: Because Host D is on a different subnet, Host B sends the frame to the default gateway. The Layer 2
destination is the router Fa0 MAC address, while the Layer 3 destination stays Host D's IP address.
Question 2
What will happen if the default gateway address is incorrectly configured on a host?
, Correct Answer choice
The host cannot communicate with other hosts in the
local network.
A ping from the host to 127.0.0.1 would not be
successful.
The host will have to use ARP to determine the correct
address of the default gateway.
The switch will not forward packets initiated by the host.
The host cannot communicate with hosts in other
✓ networks.
Explanation: A wrong default gateway usually does not stop local communication, but it prevents traffic from being
routed to other networks.
Question 3
Which scenario describes a function provided by the transport layer?
Correct Answer choice
A student has two web browser windows open in
✓ order to access two web sites. The transport layer
ensures the correct web page is delivered to the
correct browser window.
A corporate worker is accessing a web server located on
a corporate network. The transport layer formats the
screen so the web page appears properly no matter what
device is being used to view the web site.
A student is using a classroom VoIP phone to call home.
The unique identifier burned into the phone is a
transport layer address used to contact another network
device on the same network.
A student is playing a short web-based movie with sound.
The movie and sound are encoded within the transport
layer header.
Explanation: The transport layer uses port numbers to keep different application sessions separate.
Question 4
Which two statements describe features of an IPv4 routing table on a router? (Choose two.)
Correct Answer choice
The routing table lists the MAC addresses of each active
interface.
If a default static route is configured in the router, an
✓ entry will be included in the routing table with
source code S.
If there are two or more possible routes to the same
destination, the route associated with the higher metric
value is included in the routing table.
The netstat -r command can be used to display the
routing table of a router.
It stores information about routes derived from the
✓ active router interfaces.
Directly connected interfaces will have two route source
codes in the routing table: C and S.
Explanation: Static routes appear with source code S, and active router interfaces create connected/local routing
information. MAC mappings are stored in ARP tables, not routing tables.
, Question 5
A network administrator needs to keep the user ID, password, and session contents private when establishing remote
CLI connectivity with a switch to manage it. Which access method should be chosen?
Correct Answer choice
Console
AUX
Telnet
✓ SSH
Explanation: SSH encrypts remote management traffic; Telnet sends information in clear text.
Question 6
Which two statements accurately describe an advantage or a disadvantage when deploying NAT for IPv4 in a
network? (Choose two.)
Correct Answer choice
NAT improves packet handling.
NAT provides a solution to slow down the IPv4
✓ address depletion.
NAT introduces problems for some applications that
✓ require end-to-end connectivity.
NAT causes routing tables to include more information.
NAT will impact negatively on switch performance.
NAT adds authentication capability to IPv4.
Explanation: NAT lets many private hosts share fewer public IPv4 addresses, but it can interfere with applications that
require direct end-to-end connectivity.
Question 7
What technique is used with UTP cable to help protect against signal interference from crosstalk?
Correct Answer choice
wrapping a foil shield around the wire pairs
terminating the cable with special grounded connectors
encasing the cables within a flexible plastic sheath
✓ twisting the wires together into pairs
Explanation: UTP means unshielded twisted pair. The twists help cancel interference and reduce crosstalk.
Question 8
Match the header field with the appropriate layer of the OSI model.
Available options: Layer 2, Layer 3, Layer 4
Item / description Correct match
FCS (frame check sequence) Layer 2
802.2 header Layer 2
Destination MAC address Layer 2
Source IP address Layer 3
TTL Layer 3
Destination port number Layer 4
Acknowledgement number Layer 4
Explanation: Layer 2 uses frame and MAC fields, Layer 3 uses IP fields, and Layer 4 uses transport fields such as
ports and TCP acknowledgement numbers.
