IB Computer Science A2.4.3: Common Network Countermeasures

Teach common network countermeasures with a 98-slide IB Computer Science HL presentation for A2.4.3, first assessment 2027.

Help students move from naming security measures to explaining how they protect a network. Visual explanations, applied scenarios and checkpoints focus on each measure’s purpose, mechanism and the threats it addresses.

Topics covered

• Content security policies and password policies
• DDoS mitigation and email filtering
• Encrypted protocols and input validation
• Intrusion detection systems (IDS) and intrusion prevention systems (IPS)
• Multifactor authentication and SSL/TLS certificates
• Software updates and VPNs
• Security testing, employee training and wireless MAC address controls

Teaching and revision activities

• Learning objectives and a starter matching activity
• Visual workflows, comparisons and practical examples
• Checkpoints and applied scenario challenges
• IB-style practice questions with mark allocations and suggested answers
• Revision flashcards, a quick-fire identification activity and an exit ticket with answers

Visual examples include an email filtering workflow, encrypted versus unencrypted protocols and a remote-office VPN connection. Students explore prevention, detection and response, select suitable countermeasures and explain their choices.