Kali Linux RTL8812AU Setup - Driver + Monitor Mode + Injection Test

Kali Linux + RTL8812AU (WIF02)

Quick setup: install driver, enable monitor mode on the correct adapter, and run an injection test.

Authorized use only. Monitor mode and injection testing must only be performed on networks you own or have explicit permission to test.

Products used

1) Confirm the adapter is detected

lsusb
iw dev
ip link show

Identify which interface belongs to the external USB adapter.

2) Find the correct RTL8812AU driver package

sudo apt update
apt search 8812au
apt search 88xxau
Common fix (APT errors / “Not live until …”): If apt update fails due to time or signature errors, enable NTP and retry. 
sudo timedatectl set-ntp true
sudo systemctl restart systemd-timesyncd || true

sudo apt clean
sudo apt update

Look for a DKMS package such as realtek-rtl88xxau-dkms.

3) Install the driver

sudo apt install realtek-rtl88xxau-dkms

Replug the adapter or reboot if needed.

4) Enable monitor mode (IMPORTANT)

# First, list all wireless interfaces
iw dev

# Eliminate background processes that conflict with putting a network card into "Monitor Mode"
sudo airmon-ng check kill 

# Identify the EXTERNAL adapter (often wlan1, wlan2, etc.)
# Then start monitor mode on THAT interface:
# If it's a modern laptop, RTL8812AU is usually wlan1 (internal Wi-Fi is often wlan0)
# For wlan1, the command will be: sudo airmon-ng start wlan1
sudo airmon-ng start wlanX

Important: Many laptops name the internal Wi-Fi card wlan0. Do not enable monitor mode on your internal adapter by mistake.
  • External USB adapters are often wlan1, wlan2, etc.
  • Use iw dev and lsusb to confirm.

If you enabled monitor mode on the wrong interface:

# Stop monitor mode on the wrong interface
sudo airmon-ng stop wlan0mon

# Restart networking
sudo systemctl restart NetworkManager

# Eliminate background processes that conflict with putting a network card into "Monitor Mode"
sudo airmon-ng check kill 

# Identify the EXTERNAL adapter (often wlan1, wlan2, etc.)
# Then start monitor mode on THAT interface:
# If it's a modern laptop, RTL8812AU is usually wlan1 (internal Wi-Fi is often wlan0)
# For wlan1, the command will be: sudo airmon-ng start wlan1
sudo airmon-ng start wlanX

5) Injection test

sudo aireplay-ng --test wlanXmon

Stop monitor mode

sudo airmon-ng stop wlanXmon
sudo systemctl restart NetworkManager