Network Security

Network security protects the infrastructure that connects systems, applications, and users. It encompasses hardware, software, policies, and practices designed to prevent unauthorised access, misuse, and attacks on network resources.

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Defence in Depth

Defence in depth is a layered security strategy — if one control fails, another catches the attack:

┌─────────────────────────────────┐
│  Perimeter (Firewall, WAF)      │
│  ┌───────────────────────────┐  │
│  │  Network (IDS/IPS, Seg.)  │  │
│  │  ┌─────────────────────┐  │  │
│  │  │  Host (EDR, AV)     │  │  │
│  │  │  ┌───────────────┐  │  │  │
│  │  │  │  Application  │  │  │  │
│  │  │  │  ┌─────────┐  │  │  │  │
│  │  │  │  │  Data    │  │  │  │  │
│  │  │  │  └─────────┘  │  │  │  │
│  │  │  └───────────────┘  │  │  │
│  │  └─────────────────────┘  │  │
│  └───────────────────────────┘  │
└─────────────────────────────────┘

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Firewalls

Firewalls filter traffic based on rules:

Types of Firewalls