Wi-Fi Basics – How Wireless Networks Actually Work

Introduction

Before diving into reconnaissance and attacks, it’s crucial to understand the Wi-Fi basics — how wireless networks operate under the hood. These fundamentals are the key to recognizing vulnerabilities and building efficient hacking strategies.

What is Wi-Fi?

Wi-Fi is a wireless communication technology based on the IEEE 802.11 standards. It allows devices to communicate over radio waves within a limited range, replacing wired Ethernet connections.

Understanding this protocol is vital for both offensive (penetration testing) and defensive (network security) purposes.

SSID (Service Set Identifier)

The SSID is the name of a wireless network — what you see when you scan for available Wi-Fi.

Can be hidden, but still discoverable via passive sniffing
Helps identify targets during reconnaissance
Each network has a unique SSID + BSSID combo

Pro Tip: Use tools like airodump-ng to detect hidden SSIDs.

MAC Address (Media Access Control)

Each device’s Wi-Fi interface has a MAC address — a 48-bit unique identifier.

Example: 00:11:22:33:44:55
Used to track devices
Can be spoofed for anonymity or impersonation
Access points (routers) also have a MAC address (called BSSID)

Wi-Fi Encryption Types

Different encryption protocols are used to protect Wi-Fi networks:

1. WEP (Wired Equivalent Privacy)

Outdated & insecure
Easily crackable in minutes
Used mainly in legacy systems

2. WPA (Wi-Fi Protected Access)

Introduced as a patch to WEP
Still vulnerable to dictionary attacks

3. WPA2 (Most Common Today)

Uses AES encryption
Vulnerable to handshake capture + cracking
Still the de facto standard

4. WPA3 (Modern & Secure)

Not widely adopted yet
Resistant to many common attacks
Not crackable by traditional methods like aircrack-ng

Frequency Bands: 2.4 GHz vs 5 GHz

Wi-Fi operates in two primary bands:

🔵 2.4 GHz

Longer range, more interference
Channels: 1–13 (overlapping)
Better penetration through walls

🔴 5 GHz

Shorter range, faster speed
More channels, less interference
Ideal for high-speed, close-range connections

Note: Your adapter must support the band you want to work on!

Channels & Overlap

Wi-Fi operates over channels — sub-frequencies within a band.

2.4 GHz: Channels 1, 6, and 11 are most commonly used (non-overlapping)
5 GHz: More available channels with minimal overlap
Useful during scanning to identify least crowded or active channels

Tools like airodump-ng and Kismet help visualize channel usage.

Beacon Frames & Probes

Wi-Fi uses special frames to communicate:

Beacon Frames: Sent by access points to advertise presence
Probe Requests/Responses: Sent by clients searching for known SSIDs

These are essential in reconnaissance and deauthentication attacks.

Open vs Secured Networks

Network Type	Description	Vulnerabilities
Open	No password	Anyone can connect; traffic easily intercepted
WEP	Weak encryption	Easily crackable with basic tools
WPA/WPA2	Stronger encryption	Requires handshake capture for cracking
WPA3	Modern encryption	Currently hard to break

Wrapping Up

Understanding these Wi-Fi basics — SSIDs, MACs, channels, encryption, and frequency — gives you the knowledge to identify vulnerabilities and choose the right attack vector in future posts.

Next up:
🎯 Part 4 – Monitor Mode & Airodump-ng Explained

We’ll dive into real-world reconnaissance with packet sniffing and target selection.