January 20, 2019

Configuring Strong Wi-Fi (802.1X) Authentication in Linux, Part II - page 2

Supplicants and Authentication

  • December 15, 2009
  • By Eric Geier

Once you have the wpa_supplicant.conf file configured with the desired settings and network block(s), you can go ahead and give it a try. Here's an example of what you can run from the command-line:

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf

This runs the daemon in the background, uses the wlan0 network interface, and reads the configuration files from the etc directory. If you need additional help, run man wpa_supplicant to see it's manual. If you have any problems, try running the following command to see debugging information:

wpa_supplicant -i wlan0 -c /etc/wpa_supplicant.conf -d

So you don't have to run these commands after every boot, consider adding the following to the file at /etc/network/interfaces:

auto wlan0

iface wlan0 inet dhcp

��� pre-up wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf

��� post-down killall -q wpa_supplicant

Using the wpa_gui application

If the command-line isn't appealing, you can use wpa_gui. It's a graphical utility that you can use to configure most of the wpa_supplicant settings. Depending upon your Linux distribution, this may be installed with the wpa_supplicant package or may have to be installed from a separate wpa_gui package.

Figure 1 shows an example of wpa_gui in Ubuntu. It is basically a graphical version of the command-line and configuration file method. You can scan for networks and save profiles for them. Plus you can see the network status, review the event history, and configure WPS settings.

figure 1
figure 1


Getting more help

We reviewed only some aspects of wpa_supplicant. The project offers many more examples in a full configuration file. Plus you can communicate and search on their mailing list.

Eric Geier is the Founder and CEO of NoWiresSecurity, which helps businesses easily protect their Wi-Fi network with enterprise-level encryption by offering an outsourced RADIUS/802.1X authentication service called AuthenticateMyWiFi. He is also the author of many networking and computing books for brands like For Dummies and Cisco Press.


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