Now open Fern and try selecting wlan0mon . Fern must be run with root privileges:
sudo airmon-ng check kill This kills processes like NetworkManager , wpa_supplicant , etc. Kali Linux Fern Wifi Cracker No Wireless Interface Was Found
sudo apt update sudo apt install realtek-rtl88xxau-dkms Then reboot. Now open Fern and try selecting wlan0mon
sudo airmon-ng start wlan0 sudo airodump-ng wlan0mon | Problem | Solution | |----------------------------------|-----------------------------------------------| | No interface shown in iwconfig | Plug in a compatible USB Wi-Fi adapter | | Interface exists but Fern fails | Run sudo airmon-ng check kill + manual monitor mode | | Still not working | Use Wifite or aircrack-ng instead of Fern | | Internal card only | Buy a supported external adapter (~$20–40) | Final Note Fern WiFi Cracker is old and less maintained. Many modern Kali users skip it in favor of Wifite (simpler) or aircrack-ng (more control). If you’re learning Wi-Fi penetration testing, focus on those instead. sudo airmon-ng start wlan0 sudo airodump-ng wlan0mon |
| Chipset | Example Adapter | Monitor Mode | Packet Injection | |---------------|--------------------------------|--------------|------------------| | | Alfa AWUS036ACH | Yes | Yes | | RTL8187 | Alfa AWUS036H (legacy) | Yes | Yes | | AR9271 | TP-Link TL-WN722N (v1 only) | Yes | Yes | | MT7612U | Panda Wireless PAU09 | Yes | Yes |
iwconfig Or:
If you see nothing, your adapter is either not connected or not recognized. NetworkManager and other services can block the interface.