OSI Model Quiz — Test Your Networking Knowledge (20 Questions)

OSI Model Quick Reference

How to Remember the OSI Layers

Two mnemonics cover both directions, and exam questions ask for both:

• Layer 7 down to Layer 1: All People Seem To Need Data Processing, Application, Presentation, Session, Transport, Network, Data Link, Physical.
• Layer 1 up to Layer 7: Please Do Not Throw Sausage Pizza Away, Physical, Data Link, Network, Transport, Session, Presentation, Application.

The direction matters because encapsulation runs top to bottom on the sending device and decapsulation runs bottom to top on the receiving device.

The Mistakes That Cost Marks in Exams

• Confusing switches and routers. A traditional switch is Layer 2 and forwards on MAC addresses. A router is Layer 3 and forwards on IP addresses. A Layer 3 switch does both.
• Mixing up segments, packets and frames. TCP produces segments, IP produces packets, Ethernet produces frames. Exam questions often test only this distinction.
• Placing ARP. ARP resolves Layer 3 addresses to Layer 2 addresses and is usually described as sitting between the two, a common trick question.
• Forgetting that hubs are Layer 1. A hub has no addressing intelligence at all, which is exactly why it creates one big collision domain.
• Assuming OSI maps cleanly onto TCP/IP. The TCP/IP model collapses Layers 5, 6 and 7 into a single Application layer.

Frequently Asked Questions

How many questions do I need to get right to pass?

There is no formal pass mark on this quiz, but scoring 15 out of 20 or better means you have the OSI fundamentals solid enough for the CCNA and Network+ exams. Below 12, work through the layers again before moving on.

Is the OSI model still used in real networks?

No network actually runs on OSI as a protocol stack, TCP/IP won that argument decades ago. But OSI remains the shared vocabulary engineers use to describe where a problem lives. “It is a Layer 1 issue” or “that is a Layer 7 problem” is understood instantly on any support call.

What is the difference between the OSI model and the TCP/IP model?

OSI has seven layers; the TCP/IP model has four. TCP/IP merges OSI Layers 5, 6 and 7 into one Application layer, and merges Layers 1 and 2 into a Network Access layer. The middle two layers map directly.

Which layer do most network problems occur at?

Layer 1, physical connectivity. Unplugged cables, damaged connectors, bad transceivers and failed ports account for a large share of real-world faults, which is why experienced engineers check the physical layer first.

Can I retake the quiz?

Yes. Press Try Again on the results screen and the quiz resets with the score cleared. Answers stay in the same order, so use it to confirm you actually learned the explanations rather than memorised positions.

Keep Learning

Read the full breakdown in our OSI model complete guide and how to remember the 7 layers. To see which device sits at which layer, read network devices explained and hub vs switch vs router. For a Layer 2 deep dive try Ethernet frames, and for Layer 3 practice use our subnet calculator and VLAN calculator. Browse all our free networking tools.