Network fundamentals
37 free practice questions with explanations
PassNova has 37 free Cisco CCNA practice questions on Network fundamentals, each with a clear explanation. Practise them in the browser with instant feedback — 100% free, no sign-up, on any device. Updated for 2026.
Network fundamentals: example questions & answers
Here are 6 example questions from this topic. Practise the full set of 37 free in the browser.
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How many layers are there in the OSI reference model?
- A 4
- B 5
- C 7 ✓
- D 8
Answer: The OSI model has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
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At which layer of the OSI model does a router primarily operate?
- A Layer 1 (Physical)
- B Layer 2 (Data Link)
- C Layer 3 (Network) ✓
- D Layer 4 (Transport)
Answer: Routers operate at Layer 3, forwarding packets based on logical IP addresses.
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Which layer of the TCP/IP model corresponds to OSI Layers 5, 6, and 7 combined?
- A Network Access
- B Internet
- C Transport
- D Application ✓
Answer: The TCP/IP Application layer maps to the OSI Session, Presentation, and Application layers.
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Which protocol provides reliable, connection-oriented data delivery using sequencing and acknowledgements?
- A UDP
- B TCP ✓
- C ICMP
- D IP
Answer: TCP is connection-oriented and uses a three-way handshake, sequencing, and acknowledgements for reliable delivery.
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What is the size, in bits, of a MAC address?
- A 32 bits
- B 48 bits ✓
- C 64 bits
- D 128 bits
Answer: A MAC address is 48 bits long, usually written as 12 hexadecimal digits.
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Which protocol is connectionless and adds the least overhead, making it suitable for VoIP and streaming?
- A TCP
- B UDP ✓
- C FTP
- D HTTP
Answer: UDP is connectionless with no handshake or acknowledgements, giving low overhead suited to real-time traffic.