You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
Understanding networking is essential for cybersecurity. Attackers exploit network protocols and misconfigurations — defenders must understand how data flows across networks to detect and prevent intrusions.
The Open Systems Interconnection (OSI) model describes how data moves through a network in seven layers:
| Layer | Name | Function | Example Protocols |
|---|---|---|---|
| 7 | Application | User-facing services | HTTP, HTTPS, DNS, SMTP, FTP |
| 6 | Presentation | Data formatting, encryption | TLS/SSL, JPEG, ASCII |
| 5 | Session | Session management | NetBIOS, RPC |
| 4 | Transport | Reliable/unreliable delivery | TCP, UDP |
| 3 | Network | Routing and addressing | IP, ICMP, ARP |
| 2 | Data Link | Frame delivery on local network | Ethernet, Wi-Fi (802.11) |
| 1 | Physical | Physical transmission | Cables, radio signals, fibre |
Tip: Remember the layers from bottom to top with "Please Do Not Throw Sausage Pizza Away."
The TCP/IP model is a simplified, practical model used by the internet:
Subscribe to continue reading
Get full access to this lesson and all 10 lessons in this course.