CompTIA Network+ Network+ OSI Model Layers and Functions 2 — Questions and Answers
Question 1: A network technician needs to configure a device that operates at Layer 3 and makes forwarding decisions based on logical addressing. Which device should they configure?
- Switch
- Hub
- Router (Correct answer)
- Bridge
Correct answer: Router
Routers operate at Layer 3 (Network layer) and use logical IP addresses to make packet forwarding decisions.
Question 2: Which OSI layer is responsible for converting data into a format that the application layer can understand, including encryption and compression?
- Session layer
- Presentation layer (Correct answer)
- Application layer
- Transport layer
Correct answer: Presentation layer
The Presentation layer (Layer 6) handles data translation, encryption, and compression to ensure the application layer can interpret the data.
Question 3: A packet is traveling from a source host to a destination host. At which OSI layer does the packet's source and destination MAC address get added?
- Network layer
- Physical layer
- Transport layer
- Data Link layer (Correct answer)
Correct answer: Data Link layer
The Data Link layer (Layer 2) encapsulates packets into frames and adds source and destination MAC addresses.
Question 4: Which of the following protocols operates at the Session layer of the OSI model?
- TCP
- IP
- NetBIOS (Correct answer)
- Ethernet
Correct answer: NetBIOS
NetBIOS operates at the Session layer (Layer 5), managing sessions between applications on different computers.
Question 5: When data travels down the OSI model from the Application layer to the Physical layer, what is this process called?
- Decapsulation
- Encapsulation (Correct answer)
- Multiplexing
- Segmentation
Correct answer: Encapsulation
Encapsulation is the process where each OSI layer adds its own header (and sometimes trailer) as data moves down toward the Physical layer.
Question 6: A switch uses a MAC address table to forward frames. At which OSI layer does a switch primarily operate?
- Layer 1
- Layer 2 (Correct answer)
- Layer 3
- Layer 4
Correct answer: Layer 2
Traditional switches operate at Layer 2 (Data Link layer) and use MAC address tables to make forwarding decisions.
Question 7: Which OSI layer is responsible for end-to-end communication, flow control, and error recovery between two hosts?
- Network layer
- Data Link layer
- Session layer
- Transport layer (Correct answer)
Correct answer: Transport layer
The Transport layer (Layer 4) provides end-to-end communication, flow control, and error recovery using protocols like TCP.
CompTIA Network+ Network+ OSI Model Layers and Functions 2
A network technician needs to configure a device that operates at Layer 3 and makes forwarding decisions based on logical addressing.
Which device should they configure?