8821au ( 8821au.ko )
Linux Driver for USB WiFi Adapters that are based on the RTL8811AU and RTL8821AU Chipsets
- v126.96.36.199 (Realtek) (20210708)
- Plus updates from the Linux community
- IEEE 802.11 b/g/n/ac WiFi compliant
- 802.1x, WEP, WPA TKIP and WPA2 AES/Mixed mode for PSK and TLS (Radius)
- IEEE 802.11b/g/n/ac Client mode
- Supports wireless security for WEP, WPA TKIP and WPA2 AES PSK
- Supports site survey scan and manual connect
- Power saving modes
- Packet injection
- Supported interface modes
- Monitor (see
- Log level control
- LED control
- Power saving control
- VHT control (allows 80 MHz channel width in AP mode)
- SU Beamformee and MU Beamformee control
- SU Beamformer control
- DFS Channel support and control for AP mode
Note: WPA3-SAE support is in this driver, however, for it to work with current Linux distros, you will need to download, compile and install the current master of wpa_supplicant at the following site:
If there is interest, I will consider making and posting a guide. I am very busy so if anyone is interested in making a guide/checklist, I will add it to the README.
Note: A FAQ is available at the end of this document.
Problem reports go in
Problem reports should include the information obtained with the following command:
$ sudo uname -a && mokutil --sb-state && lsusb && rfkill list all && dkms status && iw dev
- x86, amd64
- ARM, ARM64
- Kernels: 4.15 - 5.11 (Realtek)
- Kernels: 5.12 - 5.15 (community support)
Tested Linux Distributions
Arch Linux (kernels 5.4 and 5.11)
Fedora (kernel 5.11)
Debian 11 (kernels 5.10 and 5.15)
Kali Linux (kernel 5.10)
Linux Mint 20.2 (Linux Mint based on Ubuntu) (kernels 5.4 and 5.11)
LMDE 4 (Linux Mint based on Debian) (kernel 4.19)
Manjaro 20.1 (kernel 5.9) and 21.1 (kernel 5.13)
Raspberry Pi OS (2021-05-07) (ARM 32 bit) (kernel 5.10)
Raspberry Pi Desktop (x86 32 bit) (kernel 4.19)
Ubuntu 20.xx (kernels 5.4 and 5.8) and 21.xx (kernels 5.11 and 5.14)
Download Locations for Tested Linux Distributions
- Alfa AWUS036ACS
- Buffalo WI-U2-433DHP
- Edimax EW-7811UTC
- Edimax EW-7811UAC
- Edimax EW-7811UCB
- ELECOM WDC-433DU2H
- GMYLE - AC450
- Netgear A6100
- Netis WF2180
- Planex GW-450S
- EDUP EP-1607
- Numerous adapters that are based on the supported chipsets.
Note: Please read "supported-device-IDs" for information about how to confirm the correct driver for your adapter.
The installation instructions are for the novice user. Experienced users are welcome to alter the installation to meet their needs.
Temporary internet access is required for installation. There are numerous ways to enable temporary internet access depending on your hardware and situation. One method is to use tethering from a phone. Another method to enable temporary internet access is to keep a WiFi adapter that uses an in-kernel driver in your toolkit.
You will need to use the terminal interface. The quick way to open a terminal: Ctrl+Alt+T (hold down on the Ctrl and Alt keys then press the T key).
An alternative terminal is to use SSH (Secure Shell) from the same or from another computer, in which case you will be in a suitable terminal after logging in, but this step requires that an SSH daemon/server has already been configured. (There are lots of SSH guides available, e.g., for the Raspberry Pi and for Ubuntu. Do not forget to secure the SSH server.)
You will need to have sufficient access rights to use
sudo, so that arbitrary commands can be executed as the
root user. (If the command
sudo echo Yes returns "Yes", with or without having to enter your password, you do have sufficient access rights.)
DKMS is used for the installation. DKMS is a system utility which will automatically recompile and install this driver when a new kernel is installed. DKMS is provided by and maintained by Dell.
It is recommended that you do not delete the driver directory after installation as the directory contains information and scripts that you may need in the future.
There is no need to disable Secure Mode to install this driver. If Secure Mode is properly setup on your system, this installation will support it.
Step 1: Open a terminal (e.g.: Ctrl+Alt+T)
Step 2: Update system package information (select the option for the OS you are using)
Note: If you do not regularly maintain your system by installing updated packages, it is a good idea to not only update system package information but also to install the updated packages followed by a system reboot. The installation can then be continued with step 3.
Option for Debian based distributions such as Ubuntu, Linux Mint, Kali and Raspberry Pi OS $ sudo apt update
Option for Arch based distributions such as Manjaro $ sudo pacman -Syu
Option for Fedora based distributions # sudo dnf -y update
Step 3: Install the required packages (select the option for the OS you are using)
Option for Raspberry Pi OS $ sudo apt install -y raspberrypi-kernel-headers bc build-essential dkms git
Option for Debian, Kali or Linux Mint Debian Edition (LMDE) $ sudo apt install -y linux-headers-$(uname -r) build-essential dkms git libelf-dev
Option for Ubuntu (all flavors) or Linux Mint $ sudo apt install -y dkms git build-essential
Options for Arch or Manjaro if using pacman $ sudo pacman -S --noconfirm linux-headers dkms git Note: If you are asked to choose a provider, make sure to choose the one that corresponds to your version of the linux kernel (for example, "linux510-headers" for Linux kernel version 5.10). If you install the incorrect version, you'll have to uninstall it and reinstall the correct version. If using other methods, please follow the instructions provided by those methods.
Option for Fedora # sudo dnf -y install git dkms kernel-devel kernel-debug-devel
Step 4: Create a directory to hold the downloaded driver
$ mkdir -p ~/src
Step 5: Move to the newly created directory
$ cd ~/src
Step 6: Download the driver
$ git clone https://github.com/morrownr/8821au-20210708.git
Step 7: Move to the newly created driver directory
$ cd ~/src/8821au-20210708
Step 8: Only for Raspberry Pi systems
Warning: This step only applies if you are installing to Raspberry Pi hardware. You should skip this step if installing to x86 or amd64 based systems.
Run a preparation script
Option for 32 bit operating systems to be installed to Raspberry Pi hardware $ ./raspi32.sh
Option for 64 bit operating systems to be installed to Raspberry Pi hardware $ ./raspi64.sh
Step 9: Run the installation script (For automated builds, use NoPrompt as an option)
$ sudo ./install-driver.sh Note: If you elect to skip the reboot at the end of the installation script, the driver may not be loaded immediately and the driver options will not be applied. Rebooting is strongly recommended.
A file called
8821au.conf will be installed in
/etc/modprobe.d by default.
Note: Step 9 of the installation script will prompt you to edit the options before rebooting.
This file will be read and applied to the driver on each system boot.
To edit the driver options file, run the
$ sudo ./edit-options.sh
Note: Documentation for Driver Options is included in the file
Removal of the Driver
Note: This script should be used in the following situations:
- the driver is no longer needed
- a fresh start with default settings is needed
- a new version of the driver needs to be installed
- a major operating system upgrade is going to be applied
Note: This script removes everything that has been installed, with the exception of the packages installed in Step 3 and the driver directory. The driver directory can and probably should be deleted in most cases after running the script.
Step 1: Open a terminal (e.g.: Ctrl+Alt+T)
Step 2: Move to the driver directory
$ cd ~/src/8821au-20210708
Step 3: Run the removal script
$ sudo ./remove-driver.sh
Recommended WiFi Router/ Access Point Settings
Note: These are general recommendations, some of which may not apply to your specific situation.
Security: Set WPA2-AES. Do not set WPA2 mixed mode or WPA or TKIP.
Channel width for 2.4 GHz: Set 20 MHz fixed width. Do not use 40 MHz or 20/40 automatic.
Channels for 2.4 GHz: Set channel 1 or 6 or 11 depending on the congestion at your location. Do not set automatic channel selection. As time passes, if you notice poor performance, recheck congestion and set channel appropriately. The environment around you can and does change over time.
Mode for 2.4 GHz: For best performance, set "N only" if you no longer use B or G capable devices.
Network names: Do not set the 2.4 GHz Network and the 5 GHz Network to the same name. Note: Unfortunately many routers come with both networks set to the same name. You need to be able to control which network that is in use.
Channels for 5 GHz: Not all devices are capable of using DFS channels (I'm looking at you Roku.) It may be necessary to set a fixed channel in the range of 36 to 48 or 149 to 161 in order for all of your devices to work on 5 GHz. (For US, other countries may vary.)
Best location for the WiFi router/access point: Near center of apartment or house, at least a couple of feet away from walls, in an elevated location. You may have to test to see what the best location is in your environment.
Check congestion: There are apps available for smart phones that allow you to check the congestion levels on WiFi channels. The apps generally go by the name of
WiFi Analyzer or something similar.
After making and saving changes, reboot the router.
Set regulatory domain to correct setting in OS
Check the current setting
$ sudo iw reg get
If you get 00, that is the default and may not provide optimal performance.
Find the correct setting here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
Set it temporarily
$ sudo iw reg set US
Note: Substitute your country code if you are not in the United States.
Set it permanently
$ sudo nano /etc/default/crda Change the last line to read: REGDOMAIN=US
Recommendations regarding USB
Moving your USB WiFi adapter to a different USB port has been known to fix a variety of problems. Problems include WiFi going on and off as well as connections coming and going.
If connecting your USB WiFi adapter to a desktop computer, use the USB ports on the rear of the computer. Why? The ports on the rear are directly connected to the motherboard which will reduce problems with interference and disconnection that can happen with front ports that use cables.
If your USB WiFi adapter is USB 3 capable then plug it into a USB 3 port.
Avoid USB 3.1 Gen 2 ports if possible as almost all currently available adapters have been tested with USB 3.1 Gen 1 (aka USB 3) and not with USB 3.1 Gen 2.
If you use an extension cable and your adapter is USB 3 capable, the cable needs to be USB 3 capable (if not, you will at best be limited to USB 2 speeds).
Some USB WiFi adapters require considerable electrical current and push the capabilities of the power available via USB port. One example is devices that use the Realtek 8814au chipset. Using a powered multiport USB extension can be a good idea in cases like this.
How to disable onboard WiFi on Raspberry Pi 3B, 3B+, 3A+, 4B and Zero W
Add the following line to /boot/config.txt
How to disable WiFi on most systems
rfkill utility can disable WiFi and Bluetooth (internal or external) on several systems, including but not limited to the Raspberry Pi.
How to forget a saved WiFi network on a Raspberry Pi
- Edit wpa_supplicant.conf
$ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
Delete the relevant WiFi network block (including the 'network=' and opening/closing braces.
Press ctrl-x followed by 'y' and enter to save the file.
Question: What interface combinations does this driver support?
Answer: None. Realtek out-of-kernel drivers, including this driver, do not support interface combinations. If you need support for interface combinations, I suggest adapters based on the Mediatek chipsets.
Question: What extended features does this driver support?
Answer: None. For extended features, you need an adapter that uses Mediatek or Atheros drivers.
Question: I bought two rtl8811au based adapters and am planning to run one of them as an AP and another as a WiFi client. How do I set that up?
Answer: You can't. Realtek drivers do not support more than one adapter with the same chipset in the same computer. However, testing has shown that the Mediatek drivers do support more than one adapter with the same chipset in the same computer.
Question: Why do you recommend Mediatek based adapters when you maintain this repo for a Realtek driver?
Answer: Many new Linux users already have adapters based on Realtek chipsets. This repo is for Linux users to support their existing adapters but my STRONG recommendation is for Linux users to seek out WiFi solutions based on Mediatek, Intel or Atheros chipsets and drivers. If users are looking at a USB solution, Mediatek and Atheros based adapters are the best solution. Realtek based USB adapters are not a good solution because Realtek does not follow Linux Wireless standards for USB WiFi adapters. Realtek drivers are problematic in many ways. You have been WARNED. For information about USB WiFi adapters: