Wi-Fi

This chapter describes common information and instructions of Wi-Fi on IoT Yocto, such as command to configure DHCP or static IP and so on.

But Wi-Fi on different platforms may have some platform-specific instructions or test results. For example, you will get different throughput on different platforms.

Station (Client) mode

Connect to a Wi-Fi AP

There are two methods to connect evaluation board to a Wi-Fi network: NetworkManager and wpa_supplicant.

NetworkManager is a high level service and should be used when possible, since it automatically configures wpa_supplicant and other system states.

Connect to a network via NetworkManager

First, make sure service NetworkManager (NetworkManager) is running:

systemctl status NetworkManager.service

You should see an output line like this:

Active: active (running)

If not, launch NetworkManager:

systemctl start NetworkManager.service

Now, please remove the old config file from /etc/wpasupplicant.conf, if wpa_supplicant has been used before. This configuration file interferes NetworkManager.

rm -rf /etc/wpasupplicant.conf

Finally, run nmcli command to configure and connect the board to WIFI with NetworkManager:

Note

Interface name <IFNAME> may be different by modules. It should be wlan0 or wlp1s0 usually. The name depends on the driver default when the module is probed.

nmcli device wifi connect <SSID> ifname <IFNAME> password <PASSWD>

nmcli would report the connection result with following log:

Device 'wlan0' successfully activated with 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'.

If everything works fine, you should be able to connect to the internet:

# Check if the board is actually connected to the internet.
ping www.google.com

Connect to a network via wpa_supplicant

Use this method only if you want to avoid using NetworkManager.

First, stop NetworkManager:

systemctl stop NetworkManager.service

To double check that NetworkManager has been stopped:

systemctl status NetworkManager.service

There should be a status log saying: Active: inactive (dead).

Now, configure /etc/wpa_supplicant.conf with this command:

wpa_passphrase <SSID> <PASSWD> > /etc/wpa_supplicant.conf

And then verify the configuration file by running the following command:

cat /etc/wpa_supplicant.conf

The generated content of wpa_supplicant.conf should be similar to this:

network={
    ssid="<SSID>"
    #psk="<PASSWD>"
    psk=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
}

Please add the following to the top of the configuration file for runtime configuration. By adding the following settings, user will be able to use wpa_cli to control the connection at runtime.

update_config=1
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel

And we also have to configure the DNS server address:

echo "nameserver x.x.x.x " > /etc/resolv.conf

After setting resolv.conf, restart systemd-resolved service:

systemctl restart systemd-resolved.service

Finally, launch wpa_supplicant with new configuration file /etc/wpasupplicant.conf:

wpa_supplicant -B -i <IFNAME> -c /etc/wpa_supplicant.conf

And you should now be able to connect to the internet:

ping www.google.com

Enable WPA3 Client

Note

IoT Yocto enables WPA3 by default. Modification of the configuration or patching of the Wi-Fi drivers should not be necessary. Before you try it, please make sure WPA3 has been enabled properly on the Wi-Fi Access Point.

WPA3 setting for NetworkManager

If user wants to enable WPA with NetworkManager, simply enable key-mgmt as sae in interface configuration file wifi.nmconnection. The configuration file should be located in /etc/NetworkManager/system-connections folder with .nmconnection filename extension. If the wireless Access Point is configured correctly, the settings should be automatically added by the NetworkManager. However, if the settings are incorrect, you can execute the sed replacement command for the configuration file to enable WPA3.

sudo sed -i -e '/key-mgmt=/s,wpa-psk,sae,' /etc/NetworkManager/system-connections/YOUR_WIFI_CONNECTION.nmconnection

The [wifi-security] section in the .nmconnection file should looks like this.

[wifi-security]
key-mgmt=sae
psk=12345679

WPA3 setting for wpa_supplicant

If wpa_supplicant is already running, use pkill to terminate it before updating new configurations.

pkill wpa_supplicant

Please add and check the following settings to /etc/wpa_supplicant.conf for enabling WPA3 support with wpa_supplicant. There are some key configurations for WPA3, for example, sae_pwe, key_mgmt, ieee80211w, and psk. The password here should use explicit content instead of encoded hex string.

update_config=1
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel
sae_pwe=0

network={
    ssid="<SSID>"
    psk="<PASSWD>"
    # psk=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    pairwise=CCMP
    group=CCMP
    key_mgmt=SAE
    ieee80211w=2
}

Finally, launch wpa_supplicant with new configuration file /etc/wpa_supplicant.conf:

wpa_supplicant -B -i <IFNAME> -c /etc/wpa_supplicant.conf

Use wpa_cli to configure wpa_supplicant

By enabling the following settings, user could use wpa_cli to control wpa_supplicant

update_config=1
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel

Here are the wpa_cli examples.

wpa_cli -i <IFNAME> remove_network all
wpa_cli -i <IFNAME> add_network
wpa_cli -i <IFNAME> set_network 0 ssid '"<SSID>"'
wpa_cli -i <IFNAME> set_network 0 pairwise CCMP
wpa_cli -i <IFNAME> set_network 0 group CCMP
wpa_cli -i <IFNAME> set_network 0 key_mgmt SAE
wpa_cli -i <IFNAME> set_network 0 psk '"<PASSWD>"'
wpa_cli -i <IFNAME> set sae_pwe 0
wpa_cli -i <IFNAME> set_network 0 ieee80211w 2
wpa_cli -i <IFNAME> enable_network 0
wpa_cli -i <IFNAME> select_network 0
wpa_cli -i <IFNAME> status

Reference Boards

Wi-Fi on different platforms may have some platform-specific instructions or test results. For example, you will get different benchmark results on different platforms. Please find more details about difference of Wi-Fi on each platform: