Computer Networks Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationale 2026 Q&A

Computer Networks Exam Practice Questions
And Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A

SECTION 1: NETWORK FUNDAMENTALS & OSI MODEL
1. What is a computer network?
A) A single computer with multiple users
B) A collection of interconnected devices that communicate and share resources
C) A software application
D) A type of database
Correct Answer: B | Rationale: A computer network is a group of interconnected
devices (computers, servers, routers, switches) that communicate with each other
to share resources, data, and services.
2. What are the two primary types of network architectures?
A) Client-Server and Peer-to-Peer (P2P)
B) LAN and WAN
C) TCP and UDP
D) IPv4 and IPv6
Correct Answer: A | Rationale: Client-Server (centralized resources) and Peer-to-
Peer (decentralized, each node is both client and server) are the two fundamental
network architectures. LAN/WAN (B) are network sizes.
3. How many layers are in the OSI (Open Systems Interconnection) model?
A) 4
B) 5
C) 7
D) 9

,Correct Answer: C | Rationale: The OSI model has 7 layers (from bottom to top):
Physical, Data Link, Network, Transport, Session, Presentation, Application. The
TCP/IP model has 4 or 5 layers.
4. What is the correct order of the OSI model layers from bottom to top?
A) Application, Presentation, Session, Transport, Network, Data Link, Physical
B) Physical, Data Link, Network, Transport, Session, Presentation, Application
C) Physical, Network, Data Link, Transport, Application, Presentation, Session
D) Network, Physical, Data Link, Transport, Session, Presentation, Application
Correct Answer: B | Rationale: The OSI model layers from bottom to top are:
Physical (1), Data Link (2), Network (3), Transport (4), Session (5), Presentation (6),
Application (7). Mnemonic: Please Do Not Throw Sausage Pizza Away.
5. Which OSI layer is responsible for routing and logical addressing (IP
addresses)?
A) Physical Layer
B) Data Link Layer
C) Network Layer
D) Transport Layer
Correct Answer: C | Rationale: The Network Layer (Layer 3) handles routing,
logical addressing (IP addresses), and packet forwarding. Routers operate at this
layer.
6. Which OSI layer is responsible for reliable data delivery and error recovery
(segments)?
A) Physical Layer
B) Data Link Layer
C) Network Layer
D) Transport Layer
Correct Answer: D | Rationale: The Transport Layer (Layer 4) provides end-to-end
communication, segmentation, flow control, and error recovery. TCP (reliable) and
UDP (unreliable) operate at this layer.

, 7. Which OSI layer is responsible for framing, MAC addressing, and error
detection?
A) Physical Layer
B) Data Link Layer
C) Network Layer
D) Transport Layer
Correct Answer: B | Rationale: The Data Link Layer (Layer 2) frames data, adds
MAC addresses, performs error detection (CRC), and handles media access control.
Switches and bridges operate at this layer.
8. Which OSI layer transmits raw bits over the physical medium?
A) Physical Layer
B) Data Link Layer
C) Network Layer
D) Transport Layer
Correct Answer: A | Rationale: The Physical Layer (Layer 1) is responsible for the
actual transmission of raw bits (0s and 1s) over the physical medium (cables, fiber,
wireless). It defines electrical/optical/mechanical characteristics.
9. Which OSI layer ensures data is in a readable format (encryption,
compression, translation)?
A) Session Layer
B) Presentation Layer
C) Application Layer
D) Transport Layer
Correct Answer: B | Rationale: The Presentation Layer (Layer 6) translates data
between the application and the network. It handles data encryption, decryption,
compression, and character encoding (e.g., ASCII, JPEG).
10. Which OSI layer establishes, manages, and terminates sessions between
applications?
A) Session Layer
B) Presentation Layer