CNIT 340 Exam 1 Actual Practice Exam:
Network Security Fundamentals with
Complete Verified Solutions
Section 1: Network Models, Standards, and Fundamental Concepts
(Questions 1-14)
Q1: Which layer of the OSI model is responsible for logical addressing and routing
between networks?
A. Data Link Layer
B. Network Layer
C. Transport Layer
D. Session Layer
Correct Answer: B
Rationale: The Network Layer (Layer 3) provides logical addressing (IP addresses) and
routing functionality to move packets between different networks. The Data Link Layer
(A) handles physical addressing (MAC addresses) on local segments. The Transport
Layer (C) manages end-to-end communication and reliability. The Session Layer (D)
establishes, manages, and terminates sessions between applications.
,Q2: In the TCP/IP model, which layer combines the functions of the OSI model's
Session, Presentation, and Application layers?
A. Internet Layer
B. Transport Layer
C. Application Layer
D. Network Interface Layer
Correct Answer: C
Rationale: The TCP/IP Application Layer encompasses OSI Layers 5-7 (Session,
Presentation, and Application), providing a simplified four-layer model. The Internet
Layer (A) corresponds to OSI Network Layer. The Transport Layer (B) is functionally
similar in both models. The Network Interface Layer (D) combines OSI Data Link and
Physical layers.
Q3: Which IEEE 802 standard defines Ethernet for wired local area networks?
A. IEEE 802.3
B. IEEE 802.11
C. IEEE 802.15
D. IEEE 802.16
Correct Answer: A
Rationale: IEEE 802.3 defines Carrier Sense Multiple Access with Collision Detection
(CSMA/CD) for Ethernet networks. IEEE 802.11 (B) defines wireless LANs (Wi-Fi). IEEE
,802.15 (C) covers wireless personal area networks including Bluetooth. IEEE 802.16 (D)
defines broadband wireless access (WiMAX).
Q4: What is the primary function of the Data Link Layer in the OSI model?
A. End-to-end reliable data delivery
B. Logical addressing and path determination
C. Node-to-node delivery and physical addressing
D. Data encryption and compression
Correct Answer: C
Rationale: The Data Link Layer (Layer 2) provides node-to-node delivery using physical
addresses (MAC addresses), framing, and error detection on local network segments.
End-to-end reliability (A) is a Transport Layer function. Logical addressing (B) occurs at
the Network Layer. Encryption and compression (D) typically occur at higher layers.
Q5: Which protocol operates at the Transport Layer and provides connection-oriented,
reliable data delivery?
A. IP
B. TCP
C. UDP
D. ICMP
Correct Answer: B
, Rationale: TCP (Transmission Control Protocol) provides connection-oriented
communication with sequencing, acknowledgments, and retransmission for reliability.
IP (A) is a Network Layer protocol. UDP (C) is connectionless and unreliable. ICMP (D) is
a Network Layer protocol for error reporting and diagnostics.
Q6: A network administrator is troubleshooting connectivity between two hosts on
different subnets. At which OSI layer should the administrator first verify that the default
gateway is correctly configured?
A. Layer 2
B. Layer 3
C. Layer 4
D. Layer 7
Correct Answer: B
Rationale: The default gateway is a Layer 3 (Network Layer) concept that enables
inter-subnet communication by providing a routing path to remote networks. Layer 2 (A)
handles local segment communication without routing. Layer 4 (C) manages transport
functions, and Layer 7 (D) handles application-specific protocols.
Q7: Which of the following best describes the encapsulation process when data moves
down the OSI stack?
A. Data is encrypted at each layer for security
B. Protocol information is added as headers (and sometimes trailers) at each layer
C. Data is compressed at the Transport Layer and decompressed at the Physical Layer
Network Security Fundamentals with
Complete Verified Solutions
Section 1: Network Models, Standards, and Fundamental Concepts
(Questions 1-14)
Q1: Which layer of the OSI model is responsible for logical addressing and routing
between networks?
A. Data Link Layer
B. Network Layer
C. Transport Layer
D. Session Layer
Correct Answer: B
Rationale: The Network Layer (Layer 3) provides logical addressing (IP addresses) and
routing functionality to move packets between different networks. The Data Link Layer
(A) handles physical addressing (MAC addresses) on local segments. The Transport
Layer (C) manages end-to-end communication and reliability. The Session Layer (D)
establishes, manages, and terminates sessions between applications.
,Q2: In the TCP/IP model, which layer combines the functions of the OSI model's
Session, Presentation, and Application layers?
A. Internet Layer
B. Transport Layer
C. Application Layer
D. Network Interface Layer
Correct Answer: C
Rationale: The TCP/IP Application Layer encompasses OSI Layers 5-7 (Session,
Presentation, and Application), providing a simplified four-layer model. The Internet
Layer (A) corresponds to OSI Network Layer. The Transport Layer (B) is functionally
similar in both models. The Network Interface Layer (D) combines OSI Data Link and
Physical layers.
Q3: Which IEEE 802 standard defines Ethernet for wired local area networks?
A. IEEE 802.3
B. IEEE 802.11
C. IEEE 802.15
D. IEEE 802.16
Correct Answer: A
Rationale: IEEE 802.3 defines Carrier Sense Multiple Access with Collision Detection
(CSMA/CD) for Ethernet networks. IEEE 802.11 (B) defines wireless LANs (Wi-Fi). IEEE
,802.15 (C) covers wireless personal area networks including Bluetooth. IEEE 802.16 (D)
defines broadband wireless access (WiMAX).
Q4: What is the primary function of the Data Link Layer in the OSI model?
A. End-to-end reliable data delivery
B. Logical addressing and path determination
C. Node-to-node delivery and physical addressing
D. Data encryption and compression
Correct Answer: C
Rationale: The Data Link Layer (Layer 2) provides node-to-node delivery using physical
addresses (MAC addresses), framing, and error detection on local network segments.
End-to-end reliability (A) is a Transport Layer function. Logical addressing (B) occurs at
the Network Layer. Encryption and compression (D) typically occur at higher layers.
Q5: Which protocol operates at the Transport Layer and provides connection-oriented,
reliable data delivery?
A. IP
B. TCP
C. UDP
D. ICMP
Correct Answer: B
, Rationale: TCP (Transmission Control Protocol) provides connection-oriented
communication with sequencing, acknowledgments, and retransmission for reliability.
IP (A) is a Network Layer protocol. UDP (C) is connectionless and unreliable. ICMP (D) is
a Network Layer protocol for error reporting and diagnostics.
Q6: A network administrator is troubleshooting connectivity between two hosts on
different subnets. At which OSI layer should the administrator first verify that the default
gateway is correctly configured?
A. Layer 2
B. Layer 3
C. Layer 4
D. Layer 7
Correct Answer: B
Rationale: The default gateway is a Layer 3 (Network Layer) concept that enables
inter-subnet communication by providing a routing path to remote networks. Layer 2 (A)
handles local segment communication without routing. Layer 4 (C) manages transport
functions, and Layer 7 (D) handles application-specific protocols.
Q7: Which of the following best describes the encapsulation process when data moves
down the OSI stack?
A. Data is encrypted at each layer for security
B. Protocol information is added as headers (and sometimes trailers) at each layer
C. Data is compressed at the Transport Layer and decompressed at the Physical Layer
