In today’s interconnected world, understanding networking basics is essential for anyone interested in cybersecurity. Whether you’re a beginner or looking to refresh your knowledge, this article will provide a clear overview of key concepts that are the foundation of networking in cybersecurity.
Protocols and Networking
Protocols are rules that manage data communication.
TCP (Transmission Control Protocol) is a widely used protocol that establishes connection-oriented communication.
IP (Internet Protocol) is responsible for addressing and routing data packets.
The OSI Model
To understand networking, It is important to be familiar with the OSI (Open Systems Interconnection) model. It standardizes and clarifies networking protocol functions through seven layers, each serving a specific purpose in network communication. Understanding these layers provides a solid foundation for grasping how data moves through a network.
The model defines the necessary communication requirements on a network by organizing them into multiple layers.
| Layer | What it does |
|---|---|
| 7 – Application | Where humans process data and information |
| 6 – Presentation | Ensures data is in a usable format |
| 5 – Session | Capable of maintaining connections |
| 4 – Transport | Data is forwarded to a service capable of handling requests |
| 3 – Network Layer | Responsible for which path packets should travel on a network |
| 2 – Data Link | Responsible for which physical device packets should go to |
| 1 – Physical | The physical infrastructure (Internet cables) to transport data |
The top 3 layers are typically implemented in software within the Operating System:
| Layer | Where it is implemented |
|---|---|
| 7 – Application | Software |
| 6 – Presentation | Software |
| 5 – Session | Software |
The bottom 3 layers are typically implemented in hardware within devices on the network, e.g. Switches, Routers and Firewalls:
| Layer | Where it is implemented |
|---|---|
| 3 – Network Layer | Hardware |
| 2 – Data Link | Hardware |
| 1 – Physical | Hardware |
Layer 4, the Transport layer, connects the software with the hardware layers.
SDN (“Software Defined Networking”) is a technology that allows more hardware layers to be implemented via software.