Is enabling monitor mode legal?

On your own network and hardware, yes. Any access to other people's networks, even just packet capture, without permission is an offense.

Why doesn't a dictionary attack work on a strong password?

Because a word in the file must exactly equal the password. A random 12+ character password is practically outside the dictionary's range.

What's the best Wi-Fi protection?

WPA2/WPA3 with a long random password, WPS disabled, and updated firmware. Hiding the SSID doesn't help much.

Is WEP still seen on real networks?

Rarely, but the aircrack-ng tool cracks it in seconds; any WEP network should be upgraded to WPA2/WPA3 immediately.

Wi-Fi Security Testing with Aircrack-ng: A Step-by-Step Guide

Wi-Fi security testing means measuring the security of your own network and finding weaknesses before attackers do — not using other people's Wi-Fi. Every exercise in this post is to be done only on your own network or with written permission.

Prerequisite: A Network Card with Monitor Mode

Monitor mode allows the card to see all packets on the airwaves, not just those of its own network. In Kali, you switch the interface to monitor mode with this command:

sudo airmon-ng start wlan0

Keep the new interface name from the output (such as wlan0mon) for the next steps. If the card doesn't support monitor mode, no other tool will work.

Step One: Capturing Packets with airodump-ng

To view the networks and their channels:

sudo airodump-ng wlan0mon

Once you find the target network, focus the capture on it and specify the output file:

sudo airodump-ng -c CHANNEL --bssid TARGET -w cap wlan0mon

Step Two: Capturing the Handshake with a Deauth Attack

For WPA/WPA2 networks you need a handshake file — the moment a client connects. The simplest way: kick the client off with deauth packets so it connects again:

sudo aireplay-ng -0 5 -a TARGET wlan0mon

After a few seconds, you'll see the handshake logged in the airodump-ng output.

Step Three: Cracking with a Dictionary

Test the handshake against a suitable wordlist (such as rockyou or a Persian-adapted dictionary):

aircrack-ng -w wordlist.txt cap.cap

Important note: this attack only cracks weak, guessable passwords. If the password is random and long, this method is practically useless.

The Main Lesson of This Exercise

The weakness of home networks is mostly not in the protocol but in the chosen password:

Choose long (12+ characters), random passwords
Use WPA2/WPA3 and turn WPS off
Change the default SSID and limit identifying information

If you want to complete your security view, continue with Network Security and CIA Concepts and Installing Kali Linux.