Network Security on One Card

Lesson notes

Explain firewalls, encryption and common attacks and which layer each protects

Key points

• Firewall: Filters traffic by rules on IPs and ports, blocking unused ports at network and transport layers.
• TLS encryption: Encrypts data between client and server so eavesdroppers on the link read nothing useful.
• Phishing: Tricks users into giving secrets, like a fake MoMo SMS asking for your PIN.
• DoS attack: Floods a server with traffic so real users cannot reach the service at all.
• Defence in depth: Combine firewalls, encryption and user awareness, because no single control secures a network alone.

Takeaway: Security needs layers: firewall, encryption and aware users.

firewallTLSphishingDoS attack