Systemd, wifi and Debian

About configuring WiFi on Debian GNU Linux

June 27, 2022 · Linux Wireless Debian

Systemd, wifi and Debian

systemd gets the control from the Linux kernel on boot for managing services on the GNU/Linux system.

Configuring Wi-Fi on Debian GNU/Linux system could be tricky.

Following steps worked for my system

Debian 11

$ cat /etc/issue
Debian GNU/Linux 11 \n \l
$

Wireless device name is wlp4s0

$ iw dev | grep Interface
        Interface wlp4s0
$

wlp4s0 entry is not configured in /etc/network/interfaces

$ cat /etc/network/interfaces | grep wlp4s0 | grep -v ^#
$

Create wlp4s0 entry in system’d network

$ pwd
/etc/systemd/network
$ cat wlan.network
[Match]
Name=wlp4s0

[Network]
DHCP=ipv4
$

Confirm if wpa_supplicant-nl80211@service is present in systemd

$ cat /lib/systemd/system/wpa_supplicant-nl80211@.service
[Unit]
Description=WPA supplicant daemon (interface- and nl80211 driver-specific
version)
Requires=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device
Before=network.target
Wants=network.target

# NetworkManager users will probably want the dbus version instead.

[Service]
Type=simple
ExecStart=/sbin/wpa_supplicant
-c/etc/wpa_supplicant/wpa_supplicant-nl80211-%I.conf -Dnl80211 -i%I

[Install]
Alias=multi-user.target.wants/wpa_supplicant-nl80211@%i.service
$

Confirm wpa_supplicant-nl80211-wlp4s0.conf file exists

$ cat /etc/wpa_supplicant/wpa_supplicant-nl80211-wlp4s0.conf  | grep -v ^#
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
ctrl_interface_group=0
update_config=1
network={
    ssid="FreeVirus"
    scan_ssid=1
    key_mgmt=WPA-PSK
    psk="n0Vacc1ne4Th1s"
}
$

Enable network, resolved and wpa_supplicant services

systemct enable systemd-networkd.service
systemctl enable systemd-resolved.service
systemctl enable wpa_supplicant-nl80211@wlp4s0.service

Reboot and get your machine connected to the wifi automatically on bootup.