Free CompTIA Network+ OSI Model Layers and Functions Questions and Answers

Question 1

A network technician is troubleshooting an issue where a user can access local network resources but cannot connect to any external websites.
Pinging the default gateway is successful, but pinging a public DNS server by its IP address fails.
At which layer of the OSI model is the problem MOST likely occurring?

Accepted Answer

Network Layer (Layer 3)

Answer

Data Link Layer (Layer 2)

Answer

Transport Layer (Layer 4)

Answer

Application Layer (Layer 7)

Question 2

Which of the following functions is primarily associated with the Data Link Layer (Layer 2) of the OSI model?

Accepted Answer

Packaging data into frames and managing access to the physical medium

Answer

Converting data into electrical signals for transmission

Answer

Managing end-to-end connections and reliability

Answer

Determining the best path for data to travel across networks

Question 3

A web browser is preparing to send a request for a webpage. It needs to ensure the data is segmented, transmitted reliably, and reassembled in the correct order at the destination. Which OSI model layer handles these responsibilities?

Accepted Answer

Transport Layer (Layer 4)

Answer

Session Layer (Layer 5)

Answer

Presentation Layer (Layer 6)

Answer

Network Layer (Layer 3)

Question 4

A user is attempting to access a secure website using HTTPS. The web server sends back data that needs to be decrypted and formatted so the user's browser can render it correctly. Which layer of the OSI model is PRIMARILY responsible for this data translation, including encryption and decryption?

Accepted Answer

Presentation Layer (Layer 6)

Answer

Application Layer (Layer 7)

Answer

Transport Layer (Layer 4)

Answer

Session Layer (Layer 5)

Question 5

Which of the following Protocol Data Units (PDUs) is associated with the Network Layer of the OSI model?

Accepted Answer

Packet

Answer

Segment

Answer

Frame

Answer

Bit

Question 6

A network administrator is configuring a firewall to block access to a specific file-sharing application that uses a well-known protocol. This protocol provides the interface between the user's software and the network. At which OSI layer does this protocol operate?

Accepted Answer

Application Layer

Answer

Network Layer

Answer

Transport Layer

Answer

Session Layer