What is Wpa_Supplicant?
In Ubuntu, wpa_supplicant is the core background daemon responsible for handling WPA and WPA2 encrypted wireless networks. It negotiates the security keys with your Wi-Fi router, ensuring your laptop or desktop stays securely connected to the internet without sending your data in plain text.
If you are running a laptop, this service is mandatory. However, if you are running an Ubuntu Server in a rack, or a desktop PC that is permanently hardwired into a switch via an Ethernet cable, you do not need wireless encryption. Leaving wpa_supplicant running in the background on a machine without a Wi-Fi card simply wastes system resources and adds an unnecessary process to your boot sequence. You can permanently disable it.
How to Disable Wpa_Supplicant on Wired Machines
You can stop this daemon using the systemctl command.
- Open your Ubuntu Terminal (shortcut:
Ctrl + Alt + T). - First, stop the service from running in the current session:
sudo systemctl stop wpa_supplicant.service- Next, disable the service so it doesn’t automatically launch the next time you reboot the server:
sudo systemctl disable wpa_supplicant.service- To ensure that absolutely no other network management tool (like NetworkManager) can accidentally trigger the service to start, you should “mask” it. Masking links the service file to
/dev/null, making it impossible to run:
sudo systemctl mask wpa_supplicant.serviceYour wired Ethernet connections will continue to function perfectly via standard networking protocols, but your system will no longer waste time loading wireless encryption daemons during startup.