WGU C172 NETWORK AND SECURITY FOUNDATIONS OA EXAM 200
ACTUAL QUESTIONS AND CORRECT ANSWERS WITH RATIONALE
ALREADY GRADED A+ NEW!!!!!!!!!!!!!!!!
1. Which OSI layer is responsible for organizing how bits are passed over the
physical layer between devices within the same collision domain?
a) Physical Layer
b) Data Link Layer
c) Network Layer
d) Transport Layer
Answer: b) Data Link Layer
Rationale: The Data Link Layer (Layer 2) is responsible for organizing bits into
frames and managing access to the physical medium using MAC addresses. It
handles communication between devices within the same collision domain .
2. Which OSI layer is related to the function of the IP protocol suite?
a) Physical Layer
b) Data Link Layer
c) Network Layer
d) Transport Layer
Answer: c) Network Layer
Rationale: The Network Layer (Layer 3) is responsible for logical addressing
and routing of data packets across different networks. The Internet Protocol (IP)
operates at this layer .
3. Which OSI layer ensures error-free packets and resends them if they are not
received correctly?
a) Network Layer
b) Data Link Layer
c) Session Layer
d) Transport Layer
Answer: d) Transport Layer
Rationale: The Transport Layer (Layer 4) provides reliable delivery of data
through error detection, correction, and retransmission of lost or corrupted packets.
TCP is a key protocol at this layer .
,4. Which protocol suite performs functions of OSI layer 4?
a) IP
b) TCP
c) ARP
d) ICMP
Answer: b) TCP
Rationale: The Transmission Control Protocol (TCP) operates at the Transport
Layer (Layer 4) of the OSI model, providing reliable, ordered delivery of data
between applications .
5. What does the "header" of an Ethernet packet consist of?
a) Data and frame check sequence only
b) Preamble, start frame delimiter, destination and source addresses, and
length/type field
c) Source address and data only
d) Length/type field and data only
Answer: b) Preamble, start frame delimiter, destination and source addresses,
and length/type field
Rationale: The Ethernet frame header contains the preamble, start frame
delimiter, destination MAC address, source MAC address, and the length/type field
.
6. What is the minimum length of an Ethernet frame from the destination MAC
address through the frame check sequence?
a) 46 bytes
b) 64 bytes
c) 128 bytes
d) 1518 bytes
Answer: b) 64 bytes
Rationale: The minimum Ethernet frame size is 64 bytes, which includes the
destination MAC address, source MAC address, length/type, data, and frame check
sequence. This ensures collision detection works properly on Ethernet networks .
7. What is the maximum length of an Ethernet frame?
a) 64 bytes
b) 512 bytes
c) 1024 bytes
d) 1518 bytes
Answer: d) 1518 bytes
, Rationale: The maximum Ethernet frame size is 1518 bytes, including the
header, data, and frame check sequence. This ensures efficient network utilization
and prevents a single station from monopolizing the network .
8. Which type of Ethernet cable can maintain 10Gbps transmission speeds through
its maximum 100-meter length?
a) CAT5e
b) CAT6
c) CAT6a
d) CAT7
Answer: c) CAT6a
Rationale: CAT6a (Augmented Category 6) is designed to support 10 Gigabit
Ethernet (10Gbps) transmission speeds over the full 100-meter distance, making it
suitable for high-performance networks .
9. Which device is used to organize network cables as they run between switches
and other network devices?
a) Router
b) Switch
c) Patch panel
d) Modem
Answer: c) Patch panel
Rationale: A patch panel provides a centralized location for organizing and
managing network cables. It allows for flexible connections between switches and
other network devices, simplifying cable management and troubleshooting .
10. Which network device is used to connect two or more network segments by
performing OSI layer 3 functions like packet-forwarding?
a) Hub
b) Switch
c) Router
d) Bridge
Answer: c) Router
Rationale: A router operates at the Network Layer (Layer 3) and forwards
packets between different networks based on logical IP addresses. It connects
network segments and determines the best path for data transmission .
11. Which command produces output showing a domain name's IP address (e.g.,
Non-authoritative answer: Name: www.google.com Address: 172.217.11.132)?
a) ping
, b) tracert
c) nslookup
d) ipconfig
Answer: c) nslookup
Rationale: The nslookup command is used to query DNS servers to translate
domain names to IP addresses or vice versa. The output shown is typical for an
nslookup query .
12. Which command should be used to manually enter the default gateway for a
computer?
a) ping
b) ipconfig
c) route
d) nslookup
Answer: c) route
Rationale: The route command is used to view and modify the IP routing table,
including manually adding or changing the default gateway. This is necessary for
configuring network routes .
13. Which network diagnostic tool displays the path packets take between two
endpoints?
a) ping
b) tracert/traceroute
c) nslookup
d) arp
Answer: b) tracert/traceroute
Rationale: Tracert (Windows) or traceroute (Linux) shows the route packets take
from the source to a destination, listing each hop with response times. This helps
diagnose network latency and routing issues .
14. Which network type is used to wire multiple PCs to a home router?
a) WAN
b) LAN
c) MAN
d) PAN
Answer: b) LAN
Rationale: A Local Area Network (LAN) connects devices within a limited area,
such as a home, office, or building. Home routers typically create a LAN to
connect multiple PCs and other devices .
ACTUAL QUESTIONS AND CORRECT ANSWERS WITH RATIONALE
ALREADY GRADED A+ NEW!!!!!!!!!!!!!!!!
1. Which OSI layer is responsible for organizing how bits are passed over the
physical layer between devices within the same collision domain?
a) Physical Layer
b) Data Link Layer
c) Network Layer
d) Transport Layer
Answer: b) Data Link Layer
Rationale: The Data Link Layer (Layer 2) is responsible for organizing bits into
frames and managing access to the physical medium using MAC addresses. It
handles communication between devices within the same collision domain .
2. Which OSI layer is related to the function of the IP protocol suite?
a) Physical Layer
b) Data Link Layer
c) Network Layer
d) Transport Layer
Answer: c) Network Layer
Rationale: The Network Layer (Layer 3) is responsible for logical addressing
and routing of data packets across different networks. The Internet Protocol (IP)
operates at this layer .
3. Which OSI layer ensures error-free packets and resends them if they are not
received correctly?
a) Network Layer
b) Data Link Layer
c) Session Layer
d) Transport Layer
Answer: d) Transport Layer
Rationale: The Transport Layer (Layer 4) provides reliable delivery of data
through error detection, correction, and retransmission of lost or corrupted packets.
TCP is a key protocol at this layer .
,4. Which protocol suite performs functions of OSI layer 4?
a) IP
b) TCP
c) ARP
d) ICMP
Answer: b) TCP
Rationale: The Transmission Control Protocol (TCP) operates at the Transport
Layer (Layer 4) of the OSI model, providing reliable, ordered delivery of data
between applications .
5. What does the "header" of an Ethernet packet consist of?
a) Data and frame check sequence only
b) Preamble, start frame delimiter, destination and source addresses, and
length/type field
c) Source address and data only
d) Length/type field and data only
Answer: b) Preamble, start frame delimiter, destination and source addresses,
and length/type field
Rationale: The Ethernet frame header contains the preamble, start frame
delimiter, destination MAC address, source MAC address, and the length/type field
.
6. What is the minimum length of an Ethernet frame from the destination MAC
address through the frame check sequence?
a) 46 bytes
b) 64 bytes
c) 128 bytes
d) 1518 bytes
Answer: b) 64 bytes
Rationale: The minimum Ethernet frame size is 64 bytes, which includes the
destination MAC address, source MAC address, length/type, data, and frame check
sequence. This ensures collision detection works properly on Ethernet networks .
7. What is the maximum length of an Ethernet frame?
a) 64 bytes
b) 512 bytes
c) 1024 bytes
d) 1518 bytes
Answer: d) 1518 bytes
, Rationale: The maximum Ethernet frame size is 1518 bytes, including the
header, data, and frame check sequence. This ensures efficient network utilization
and prevents a single station from monopolizing the network .
8. Which type of Ethernet cable can maintain 10Gbps transmission speeds through
its maximum 100-meter length?
a) CAT5e
b) CAT6
c) CAT6a
d) CAT7
Answer: c) CAT6a
Rationale: CAT6a (Augmented Category 6) is designed to support 10 Gigabit
Ethernet (10Gbps) transmission speeds over the full 100-meter distance, making it
suitable for high-performance networks .
9. Which device is used to organize network cables as they run between switches
and other network devices?
a) Router
b) Switch
c) Patch panel
d) Modem
Answer: c) Patch panel
Rationale: A patch panel provides a centralized location for organizing and
managing network cables. It allows for flexible connections between switches and
other network devices, simplifying cable management and troubleshooting .
10. Which network device is used to connect two or more network segments by
performing OSI layer 3 functions like packet-forwarding?
a) Hub
b) Switch
c) Router
d) Bridge
Answer: c) Router
Rationale: A router operates at the Network Layer (Layer 3) and forwards
packets between different networks based on logical IP addresses. It connects
network segments and determines the best path for data transmission .
11. Which command produces output showing a domain name's IP address (e.g.,
Non-authoritative answer: Name: www.google.com Address: 172.217.11.132)?
a) ping
, b) tracert
c) nslookup
d) ipconfig
Answer: c) nslookup
Rationale: The nslookup command is used to query DNS servers to translate
domain names to IP addresses or vice versa. The output shown is typical for an
nslookup query .
12. Which command should be used to manually enter the default gateway for a
computer?
a) ping
b) ipconfig
c) route
d) nslookup
Answer: c) route
Rationale: The route command is used to view and modify the IP routing table,
including manually adding or changing the default gateway. This is necessary for
configuring network routes .
13. Which network diagnostic tool displays the path packets take between two
endpoints?
a) ping
b) tracert/traceroute
c) nslookup
d) arp
Answer: b) tracert/traceroute
Rationale: Tracert (Windows) or traceroute (Linux) shows the route packets take
from the source to a destination, listing each hop with response times. This helps
diagnose network latency and routing issues .
14. Which network type is used to wire multiple PCs to a home router?
a) WAN
b) LAN
c) MAN
d) PAN
Answer: b) LAN
Rationale: A Local Area Network (LAN) connects devices within a limited area,
such as a home, office, or building. Home routers typically create a LAN to
connect multiple PCs and other devices .
