Technologies · Year 9

Active learning ideas

Firewalls and Network Security Devices

Active learning works well for this topic because students need to move beyond abstract definitions and see how security devices actually function in real networks. Hands-on labs and group design tasks let them test rules, spot threats, and build configurations, turning theoretical ideas into concrete understanding.

• ACARA Content Descriptions
• AC9DT10K03

• 35–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Simulation Game
• 45 min · Pairs

Simulation Lab: Firewall Rule Setup

Students access an online firewall simulator and create rules to allow web traffic while blocking unauthorized ports. They launch test packets from virtual attackers and log results. Pairs troubleshoot and refine rules based on feedback.

Explain how a firewall protects a network from unauthorized access.

Facilitation Tip

During the firewall rule setup lab, circulate and ask students to explain the purpose of each rule they create before saving it, ensuring they connect the syntax to real-world filtering logic.

What to look for

Present students with a scenario: 'A user in your office tries to access a known malicious website.' Ask them to identify which security device (firewall, IDS, IPS, proxy) would most likely detect or block this activity and explain why in one sentence.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 02

• Simulation Game
• 50 min · Small Groups

Group Design: Office Network Security

Small groups sketch a network diagram for a small office, placing firewalls, IDS, and proxies. They justify choices against given threats and present to the class for peer feedback. Refine designs incorporating suggestions.

Differentiate between different types of network security devices and their functions.

Facilitation Tip

For the office network security design, assign groups specific roles (e.g., firewall admin, IDS analyst) so students must justify their device choices based on the network’s needs.

What to look for

Pose the question: 'Imagine you are designing security for a small online store. What are the top three security devices you would prioritize and why? What specific types of threats are you trying to prevent with each?' Facilitate a class discussion comparing student choices.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 03

• Simulation Game
• 35 min · Pairs

Threat Matching: Device Functions

In pairs, students draw threat cards like DDoS or phishing and match them to devices such as IPS or VPNs. They explain defenses in writing and role-play a defense scenario. Share best matches whole class.

Design a basic network security configuration for a small office.

Facilitation Tip

In the threat matching activity, provide printed cards with attack patterns and device functions, then have groups physically move the cards to correct pairings while defending their choices to peers.

What to look for

On an index card, have students define 'firewall' in their own words and list two specific types of traffic it might block. Then, ask them to name one other network security device and briefly describe its function.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 04

• Simulation Game
• 40 min · Individual

Virtual Network Build: Packet Tracer Challenge

Using Cisco Packet Tracer, individuals build a simple LAN with firewall and IDS. Test connectivity and simulate attacks, then document security logs. Pairs compare setups for improvements.

Explain how a firewall protects a network from unauthorized access.

Facilitation Tip

While building the Virtual Network Packet Tracer model, pause at key steps to ask students to predict what will happen if a packet violates a firewall rule, reinforcing cause-and-effect understanding.

What to look for

Present students with a scenario: 'A user in your office tries to access a known malicious website.' Ask them to identify which security device (firewall, IDS, IPS, proxy) would most likely detect or block this activity and explain why in one sentence.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

A few notes on teaching this unit

Research shows students grasp abstract security concepts better when they interact with real tools and scenarios, not just slides or lectures. Avoid overwhelming them with too many device types at once; instead, build understanding step-by-step through guided practice. Emphasize that security is about trade-offs—protection versus usability—and have students articulate these balances during discussions.

Students will demonstrate mastery by correctly configuring firewall rules that allow safe traffic while blocking threats, identifying the roles of IDS and IPS in threat scenarios, and explaining how proxies and VPNs contribute to layered security. They should also justify their choices with clear reasoning about risks and protections.

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Watch Out for These Misconceptions

• During the Simulation Lab: Firewall Rule Setup, watch for students who believe firewall rules block all external traffic completely.

  During the Simulation Lab: Firewall Rule Setup, redirect students by asking them to test HTTPS traffic to a trusted site and observe the firewall logs showing allowed connections, then have them modify rules to block only unsafe traffic while keeping HTTPS open.

• During the Threat Matching: Device Functions activity, watch for students who think intrusion detection systems prevent attacks automatically.

  During the Threat Matching: Device Functions activity, have groups physically move IDS and IPS cards to attack scenarios, then use the lab’s alert logs to show that IDS generates warnings while IPS drops packets, making the distinction clear through direct evidence.

• During the Group Design: Office Network Security task, watch for students who assume small networks like home offices do not need security devices.

  During the Group Design: Office Network Security task, provide a scenario with a small online store and ask groups to justify their device choices by identifying specific threats (e.g., SQL injection, unauthorized access) that even small networks face, using peer reviews to reinforce the need for layered security.

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Methods used in this brief

• Simulation Game