Introduction to Basic Network Security Concepts - 18/05/2025

What is Network Security?

Network security is a set of policies, configurations, and practices designed to protect the integrity, confidentiality, and availability of data within a network.

Every time you connect to the Internet — at home, at work, or on a mobile device — you’re using a network that can be vulnerable if not properly secured.

Key Concepts You Should Know

🔒 Firewall

A firewall is a barrier that filters incoming and outgoing network traffic. It can be hardware- or software-based, and its main purpose is to block unauthorized access while allowing legitimate connections.

Example: blocking port 23 (Telnet) to prevent attacks on outdated services.

🌐 VPN (Virtual Private Network)

A VPN encrypts your network traffic and routes it through a secure server, masking your real IP address and protecting your data on untrusted networks.

✅ Perfect for public Wi-Fi, like in coffee shops or airports.

📊 IDS / IPS

• IDS (Intrusion Detection System): detects suspicious activity on the network.
• IPS (Intrusion Prevention System): not only detects, but blocks threats automatically.

Popular tools: Snort, Suricata.

🔐 Network Encryption

Encryption ensures that data can only be read by those with the correct key. It applies to both internal communications and external services (such as HTTPS).

Think of encryption as a lock that only you and the recipient can open.

Basic Best Practices to Secure Your Network

• Change default router and device passwords.
• Keep firmware and software up to date.
• Use WPA2 or WPA3 encryption on Wi-Fi networks.
• Set up a separate guest network.
• Regularly check which devices are connected.

Network security isn’t just for experts or large organizations. Even a home network can be targeted if not properly protected.
Understanding these concepts empowers you to make safer decisions and protect your digital environment.