🧩 1. What is Network Security?
Network Security involves protecting the integrity, confidentiality, and availability of data as it travels across or is stored within a network. It includes both hardware and software technologies, as well as policies and procedures.
🕷️ 2. Common Network Threats
| Threat | Description | Example |
|---|---|---|
| Malware | Malicious software such as viruses, worms, trojans | A trojan disguised as a legitimate email attachment |
| Phishing | Tricking users into revealing sensitive information | Fake login pages imitating banks or services |
| Man-in-the-Middle (MitM) | Intercepting communication between two parties | Session hijacking on public Wi-Fi |
| Denial of Service (DoS) | Overloading a service to make it unavailable | Flooding a web server with fake requests |
| Packet Sniffing | Capturing data packets on a network | Using Wireshark to monitor unencrypted traffic |
| Spoofing | Faking the identity of a device or user | IP or MAC address spoofing |
🔐 3. Key Network Security Concepts
a. CIA Triad
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Confidentiality – Keeping data private
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Integrity – Ensuring data is not altered
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Availability – Ensuring resources are accessible when needed
b. Authentication & Authorization
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Verifying identity (username/password, MFA)
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Controlling access rights
c. Encryption
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Secures data in transit and at rest (e.g., HTTPS, VPNs)
🛡️ 4. Basic Network Security Tools
| Tool | Use |
|---|---|
| Firewall | Filters incoming/outgoing traffic |
| IDS/IPS | Intrusion Detection/Prevention Systems |
| VPN | Encrypts connections over insecure networks |
| Wireshark | Packet sniffing and analysis |
| Nmap | Network scanning and host discovery |
🧠 5. Best Practices
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Keep systems and software updated
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Use strong, unique passwords
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Enable multi-factor authentication (MFA)
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Monitor logs and network traffic
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Segment the network (use VLANs)
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Regularly back up data