wpa_supplicant

2 minutes read
blog • linux

Establishing an automatic wifi connection through wpa_supplicant

This is a small step by step guide how to set up wifi and have it run and managed by systemd on every boot.

1) install wpa_supplicant & dialog (if you want to use wifi-menu for testing purposes)

Then create a default wpa_supplicant.conf in /etc/wpa_supplicant/wpa_supplicant.conf

ctrl_interface=/run/wpa_supplicant
update_config=1

Find out interface name

ip a

If you are not sure, you can use some ncurses tool like wifi-menu to set up your connection first (it also uses wpa_supplicant) and then come back to set up wpa_supplicant manually.

Scan for networks

[yabbes@x220 ~]$ wpa_cli
wpa_cli v2.6
Selected interface 'wlp3s0'

Interactive mode

> scan

OK

<3>CTRL-EVENT-SCAN-STARTED
<3>CTRL-EVENT-SCAN-RESULTS

# print the results

> scan_results

OK 
# take note of your SSID and add it as network 0
> add_network 0
0
> set_network 0 ssid "SSID"
OK
> set_network 0 psk "passphrase"
OK
> enable_network 0
OK
> save_config
OK

now exit wpa_cli and take note that your settings have been saved in /etc/wpa_supplicant/wpa_supplicant.conf

[root@x220 yabbes]# cat /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=/run/wpa_supplicant
update_config=1

network={
        ssid="SSID"
        psk="passphrase"
}

If we want to enable this unit through systemd it expects a naming convention like wpa_supplicant-<interface>.conf so let’s proceed

mv wpa_supplicant.conf wpa_supplicant-<interface>.conf

# enable and start the systemd service
systemctl enable wpa_supplicant@<interface>.service
systemctl start wpa_supplicant@<interface>.service

# now to acquire an ip address via dhcpcd
dhcpcd <interface>

# and to do so on every boot we register it as a service
systemctl enable dhcpcd@<interface>

That’s it, it should have worked for you and you can finally ping 8.8.8.8