Computer Science · 10th Grade

Active learning ideas

The OSI Model: Layers 1-3

Active learning works for the OSI Model because abstract networking concepts become concrete when students manipulate cables, configure devices, and analyze real traffic. Moving between hands-on stations and digital simulations helps students connect the physical transmission of bits to the logical assignment of addresses, addressing common confusion about where each layer’s role begins and ends.

• Common Core State Standards
• CSTA: 3A-NI-04

• 25–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: OSI Layers 1-3

Create three stations: physical (connect devices with cables to send bits via flashlight Morse code), data link (add MAC labels to frames on paper and check for 'errors' with checksum dice), network (route paper packets using IP maps). Groups rotate every 10 minutes, documenting layer functions. Debrief as a class.

Explain the primary function of the network layer in data routing.

Facilitation Tip

During Station Rotation, circulate and ask each group to explain one decision they made about cable selection or device configuration and which OSI layer that decision affects.

What to look for

Provide students with a scenario: 'A student in your class tries to access a website.' Ask them to write one sentence explaining the role of the network layer and one sentence explaining the role of the data link layer in this scenario.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Jigsaw
• 30 min · Pairs

Packet Tracer Simulation: Layer Walkthrough

Pairs load Cisco Packet Tracer, configure a simple LAN with switches and routers. Send pings, observe encapsulation from physical bits to network packets. Annotate screenshots showing MAC to IP shifts and error checks.

Differentiate between MAC addresses and IP addresses.

Facilitation Tip

While students use Packet Tracer, pause the simulation at key moments and ask them to predict what the next layer will add to the packet before it continues.

What to look for

Present students with a list of terms (e.g., MAC address, IP address, bit, frame, router). Ask them to categorize each term by the OSI layer (Physical, Data Link, or Network) it primarily belongs to and briefly justify their choice for one term.

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

Activity 03

• Jigsaw
• 35 min · Pairs

Wireshark Hunt: Real Traffic Analysis

Individuals or pairs capture local network traffic with Wireshark. Filter for Ethernet frames and IP packets, identify MAC/IP addresses, and spot error detection fields. Share findings in a gallery walk.

Analyze how errors are detected and corrected at the data link layer.

Facilitation Tip

In the Wireshark Hunt, have students save their captures and annotate one frame with the layer responsible for each header field they observe.

What to look for

Pose the question: 'Why is it important to have both MAC addresses for local communication and IP addresses for global communication?' Facilitate a class discussion where students explain the differences and necessity of each addressing scheme.

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

Activity 04

• Jigsaw
• 25 min · Whole Class

Address Scavenger Hunt: MAC vs IP

Whole class uses command line tools to find device MAC and IP addresses. Map them on a board, discuss local vs global roles. Extend to simulate routing failures without proper IP.

Explain the primary function of the network layer in data routing.

Facilitation Tip

For the Address Scavenger Hunt, require each team to present one MAC address and one IP address they found and explain why each belongs to a different layer.

What to look for

Provide students with a scenario: 'A student in your class tries to access a website.' Ask them to write one sentence explaining the role of the network layer and one sentence explaining the role of the data link layer in this scenario.

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

A few notes on teaching this unit

Teach the OSI layers by starting with physical connections students can see and touch, then layering on addressing and routing concepts that build logically. Avoid overwhelming students with all seven layers at once; focus on layers 1-3 first, using analogies like ‘the postal system’ to explain how MAC addresses work locally while IP addresses handle global delivery. Research shows that students grasp abstract layers best when they first manipulate concrete tools like cables, NICs, and routers before moving to simulations and packet analysis.

By the end of these activities, students will confidently explain the unique purpose of layers 1-3, distinguish between MAC and IP addressing, and trace how data moves from raw bits to routed packets. You’ll see students pointing to devices and saying, ‘This is where the data link layer adds the frame’ or ‘That router is doing the network layer’s job’ without prompting.

---

Watch Out for These Misconceptions

• During Station Rotation, watch for students assuming MAC and IP addresses are interchangeable or that both are used for every network hop.

  Use the Address Scavenger Hunt to have students compare MAC addresses before and after a router hop; they will notice the MAC changes with each hop while the IP remains the same, correcting the misconception directly through observation.

• During Station Rotation, watch for students attributing error detection and routing to the physical layer.

  When testing cables in Station Rotation, have students note that physical layer errors like signal degradation produce corrupted bits but no addressing or correction occurs. Then connect a data link layer device and show how frames and CRC checksums are added to correct errors.

• During Packet Tracer Simulation, watch for students claiming the data link layer routes data across the internet.

  Pause the simulation at a router and ask students to explain what the router is doing. Use the visual path to show that the data link layer operates within a local segment while the router, a network layer device, forwards the packet to the next segment.

---

Methods used in this brief

• Stations Rotation
• Jigsaw