NCTI Progression Field Tech 4–5 Final Exam
150 Practice Questions with Verified Answers & Detailed
Rationales
SECTION 1: NETWORK FUNDAMENTALS & OSI MODEL (Questions
1–30)
Q1. Which small network is private to an organization, sharing a common
communications line linking together devices such as computers, printers, and
other peripherals?
A. Wide Area Network (WAN)
B. Local Area Network (LAN)
C. Metropolitan Area Network (MAN)
D. Personal Area Network (PAN)
Answer: B. Local Area Network (LAN)
Rationale: A LAN is a private network confined to a small geographic area, like an office
or building, where devices share a common communications line. WANs cover larger
geographic areas; MANs cover metropolitan areas; PANs are personal device networks .
Q2. Which of the following is a unique address that is physically assigned to
devices such as a modem or network interface card (NIC)?
A. IP address
B. MAC address
C. Port number
D. Hostname
,Answer: B. MAC address
Rationale: A Media Access Control (MAC) address is a unique 48-bit (or 64-bit) identifier
physically assigned to a network interface by its manufacturer. The IEEE coordinates the
assignment of Organizationally Unique Identifiers (OUIs) to ensure global uniqueness .
Q3. Which two layers of the OSI reference model are combined in the TCP/IP
model's Network Access Layer?
A. Session and Presentation Layers
B. Data Link Layer and Physical Layer
C. Network and Transport Layers
D. Application and Session Layers
Answer: B. Data Link Layer and Physical Layer
Rationale: The TCP/IP Network Access Layer (also called Link Layer) combines the
functions of the OSI Physical and Data Link layers. It handles the physical transmission of
data over the network medium .
Q4. Which protocol has four numeric fields, each 8 binary bits long, called
"octets"?
A. IPv6
B. IPv4
C. TCP
D. UDP
Answer: B. IPv4
Rationale: IPv4 addresses consist of four octets (8-bit numbers) separated by periods,
forming a 32-bit address (e.g., 192.168.1.1). IPv6 uses 128-bit addresses in hexadecimal
format .
,Q5. Which OSI layer is responsible for evaluating and acting upon a packet's IP
address?
A. Physical Layer
B. Data Link Layer
C. Network Layer
D. Transport Layer
Answer: C. Network Layer
Rationale: The Network Layer (Layer 3) uses logical addresses (IP addresses) to route
packets across multiple networks. Routers operate at this layer .
Q6. What does the Data Link Layer process?
A. The physical address of a device (MAC)
B. The logical address of a device (IP)
C. The port number of an application
D. The session identifier
Answer: A. The physical address of a device (MAC)
Rationale: The Data Link Layer (Layer 2) processes and uses MAC addresses to deliver
frames between devices on the same local network. It encapsulates packets into frames
and adds physical addressing .
Q7. What occurs when a datagram is sent to a 127.x.y.z address?
A. It is sent to the default gateway
B. It loops back inside the host and never leaves the NIC
C. It is broadcast to all devices on the network
D. It is discarded by the router
Answer: B. It loops back inside the host and never leaves the NIC
Rationale: The 127.0.0.0/8 address block is reserved for loopback testing. A packet sent
to a 127.x.y.z address is immediately returned to the sending software without ever
leaving the network interface card. This is used for testing network software without
physical transmission .
, Q8. Which of the following data services does a business use for dedicated services
such as hosting a website, email, and FTP?
A. Dynamic IP addressing
B. Static IP addressing
C. DHCP addressing
D. APIPA addressing
Answer: B. Static IP addressing
Rationale: Static IP addresses are manually configured and do not change. Businesses
use them for servers hosting websites, email services, and FTP because the address must
remain constant for external clients to connect reliably .
Q9. What is missing from this list of settings for static IP configuration: IP address,
Preferred DNS server, Alternate DNS server, and Subnet mask?
A. MAC address
B. Default gateway
C. Hostname
D. Domain name
Answer: B. Default gateway
Rationale: Static IP configuration requires four essential settings: IP address, subnet
mask, default gateway, and DNS servers. The default gateway is the router that provides
access to networks outside the local subnet .
Q10. What is the IP address class of 68.56.189.17?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: A. Class A
150 Practice Questions with Verified Answers & Detailed
Rationales
SECTION 1: NETWORK FUNDAMENTALS & OSI MODEL (Questions
1–30)
Q1. Which small network is private to an organization, sharing a common
communications line linking together devices such as computers, printers, and
other peripherals?
A. Wide Area Network (WAN)
B. Local Area Network (LAN)
C. Metropolitan Area Network (MAN)
D. Personal Area Network (PAN)
Answer: B. Local Area Network (LAN)
Rationale: A LAN is a private network confined to a small geographic area, like an office
or building, where devices share a common communications line. WANs cover larger
geographic areas; MANs cover metropolitan areas; PANs are personal device networks .
Q2. Which of the following is a unique address that is physically assigned to
devices such as a modem or network interface card (NIC)?
A. IP address
B. MAC address
C. Port number
D. Hostname
,Answer: B. MAC address
Rationale: A Media Access Control (MAC) address is a unique 48-bit (or 64-bit) identifier
physically assigned to a network interface by its manufacturer. The IEEE coordinates the
assignment of Organizationally Unique Identifiers (OUIs) to ensure global uniqueness .
Q3. Which two layers of the OSI reference model are combined in the TCP/IP
model's Network Access Layer?
A. Session and Presentation Layers
B. Data Link Layer and Physical Layer
C. Network and Transport Layers
D. Application and Session Layers
Answer: B. Data Link Layer and Physical Layer
Rationale: The TCP/IP Network Access Layer (also called Link Layer) combines the
functions of the OSI Physical and Data Link layers. It handles the physical transmission of
data over the network medium .
Q4. Which protocol has four numeric fields, each 8 binary bits long, called
"octets"?
A. IPv6
B. IPv4
C. TCP
D. UDP
Answer: B. IPv4
Rationale: IPv4 addresses consist of four octets (8-bit numbers) separated by periods,
forming a 32-bit address (e.g., 192.168.1.1). IPv6 uses 128-bit addresses in hexadecimal
format .
,Q5. Which OSI layer is responsible for evaluating and acting upon a packet's IP
address?
A. Physical Layer
B. Data Link Layer
C. Network Layer
D. Transport Layer
Answer: C. Network Layer
Rationale: The Network Layer (Layer 3) uses logical addresses (IP addresses) to route
packets across multiple networks. Routers operate at this layer .
Q6. What does the Data Link Layer process?
A. The physical address of a device (MAC)
B. The logical address of a device (IP)
C. The port number of an application
D. The session identifier
Answer: A. The physical address of a device (MAC)
Rationale: The Data Link Layer (Layer 2) processes and uses MAC addresses to deliver
frames between devices on the same local network. It encapsulates packets into frames
and adds physical addressing .
Q7. What occurs when a datagram is sent to a 127.x.y.z address?
A. It is sent to the default gateway
B. It loops back inside the host and never leaves the NIC
C. It is broadcast to all devices on the network
D. It is discarded by the router
Answer: B. It loops back inside the host and never leaves the NIC
Rationale: The 127.0.0.0/8 address block is reserved for loopback testing. A packet sent
to a 127.x.y.z address is immediately returned to the sending software without ever
leaving the network interface card. This is used for testing network software without
physical transmission .
, Q8. Which of the following data services does a business use for dedicated services
such as hosting a website, email, and FTP?
A. Dynamic IP addressing
B. Static IP addressing
C. DHCP addressing
D. APIPA addressing
Answer: B. Static IP addressing
Rationale: Static IP addresses are manually configured and do not change. Businesses
use them for servers hosting websites, email services, and FTP because the address must
remain constant for external clients to connect reliably .
Q9. What is missing from this list of settings for static IP configuration: IP address,
Preferred DNS server, Alternate DNS server, and Subnet mask?
A. MAC address
B. Default gateway
C. Hostname
D. Domain name
Answer: B. Default gateway
Rationale: Static IP configuration requires four essential settings: IP address, subnet
mask, default gateway, and DNS servers. The default gateway is the router that provides
access to networks outside the local subnet .
Q10. What is the IP address class of 68.56.189.17?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: A. Class A
