How to Connect to Wi-Fi via the Terminal in Debian: 3 Proven Methods

Connecting to a wireless network via a terminal in Debian or its derivatives (for example, Ubuntu Server, Raspberry Pi OS) may seem like a daunting task for beginners. However, this skill is indispensable when a graphical interface is not available—for example, on a server without GUI, in a restored system or when configuring remotely via SSHUnlike Windows or macOS, where connecting to Wi-Fi is intuitive, Linux requires knowledge of specific commands and utilities.

In this article we will look at three main methods: using NetworkManager (through nmcli), manual tuning with wpa_supplicant and low-level commands iwconfig/ifconfigEach method has its advantages: nmcli easier for everyday tasks, wpa_supplicant more reliable for servers, and manual commands will help in emergency situations. We will also cover common errors (for example, "Device not managed") and ways to eliminate them.

Before you begin, make sure your Wi-Fi adapter is supported by the Linux kernel. To do this, run the command lspci | grep -i wireless (for PCI devices) or lsusb (for USB adapters). If the adapter is not detected, you may need to install proprietary drivers (for example, for chips) Broadcom).

1. Connecting via NetworkManager (nmcli)

NetworkManager — a standard network management tool in most Debian distributions. The utility nmcli allows you to manage connections from a terminal without a graphical interface. This method is suitable for desktop systems and servers with NetworkManager.

To connect to Wi-Fi:

1. Check NetworkManager status:

   sudo systemctl status NetworkManager

   If the service is not active, start it:

   sudo systemctl start NetworkManager

2. Get a list of available networks:

   nmcli device wifi list

   Or refresh the list if the networks are not displayed:

   nmcli device wifi rescan

3. Connect to the network:

   nmcli device wifi connect "NETWORK_NAME" password "PASSWORD"

   Replace NETWORK_NAME And PASSWORD for up-to-date data. For hidden networks, add a flag hidden yes.

If the connection was successful, check the status:

nmcli connection show

Or look at the IP address:

ip a show wlan0

Adapter enabled (rfkill unblock wifi)|NetworkManager service active|Networks displayed in nmcli device wifi list|Password entered correctly-->

⚠️ Attention: If the team nmcli device wifi list returns an error "Error: Device 'wlan0' is not active", check if the adapter is disabled programmatically by the command rfkill listUnlock it with rfkill unblock wifi.

2. Manual connection with wpa_supplicant

Utility wpa_supplicant — a more flexible and reliable way to connect to Wi-Fi, especially on servers without NetworkManagerIt supports modern safety standards (WPA3, 802.1X) and allows you to save configurations in a file /etc/wpa_supplicant/wpa_supplicant.conf.

Setup instructions:

1. Install wpa_supplicant (if not installed):

   sudo apt update && sudo apt install wpa-supplicant

2. Generate a configuration file:

   wpa_passphrase "NETWORK_NAME" "PASSWORD" | sudo tee /etc/wpa_supplicant/wpa_supplicant.conf

   This command will create an encrypted file with settings.

3. Connect to the network:

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

   Flag -B runs the process in the background.

4. Obtain an IP address via DHCP:

   sudo dhclient wlan0

To make the connection automatically at boot, add to /etc/network/interfaces:

auto wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

3. Low-level connection with iwconfig and ifconfig

If NetworkManager And wpa_supplicant are not available, you can connect to an open network or a network with WEP- encryption (not recommended!) using basic utilities iwconfig And ifconfigThis method is appropriate for minimalistic systems or for diagnostics.

Warning: WEP encryption is outdated and insecure. Use this method only for testing or connecting to open networks.

1. Check the wireless interface name:

   iwconfig

   Usually it is wlan0 or wlp3s0.

2. Connect to an open network:

   sudo iwconfig wlan0 essid "NETWORK_NAME" key off

3. Get an IP address:

   sudo dhclient wlan0

4. For WEP network (not recommended!):

   sudo iwconfig wlan0 essid "NETWORK_NAME" key "PASSWORD_IN_HEX"

   The password must be in hex format (For example, 1234567890 → 31323334353637383930).

⚠️ Attention: Teams ifconfig And iwconfig are considered obsolete in newer distributions. It is recommended to use them instead. ip And iwFor example, to view networks:

sudo iw dev wlan0 scan | grep SSID

sudo apt install wireless-tools

However, for modern systems it is better to use iw from the package iw (already pre-installed in most distributions).-->

4. Diagnosing connection problems

If your Wi-Fi isn't connecting, start by checking the following:

• 🔍 Is the adapter turned on? Check with rfkill listIf the adapter is blocked, unlock it:

  rfkill unblock wifi

• 📡 Does the system see networks? Perform a scan:

  sudo iw dev wlan0 scan | grep SSID

  If there are no networks, the problem may be in the driver or antenna.

• 🔑 Is the password correct? Make sure your password is entered correctly (case-sensitive!). To test, create a test config:

  wpa_passphrase "NETWORK_NAME" "PASSWORD"

• 🔧 Is the driver loaded? Check kernel logs:

  dmesg | grep wlan

  If there are errors of the type "firmware missing", install proprietary drivers (for example, for Broadcom).

If the problem persists, check the logs. wpa_supplicant:

journalctl -u wpa_supplicant -b

Or check the network status:

ip link show wlan0

1) Lack of/incorrect installation of drivers.

2) Adapter lock (rfkill).

3) Errors in configuration files (wpa_supplicant.conf or /etc/network/interfaces).-->

5. Automatic connection on boot

To connect Wi-Fi automatically after a reboot, set up autostart wpa_supplicant And dhclient:

1. Edit /etc/network/interfaces:

   auto wlan0
   iface wlan0 inet dhcp
   wpa-ssid NETWORK_NAME
   wpa-psk PASSWORD

   Note: The password must be in hex format (generate it using wpa_passphrase).
2. Alternatively, for systemd:

   Create a service /etc/systemd/system/wpa_supplicant.service:

   [Unit]
   Description=WPA supplicant
   After=sys-subsystem-net-devices-wlan0.device
   
   [Service]
   Type=simple
   ExecStart=/sbin/wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf -D nl80211,wext
   ExecStop=/sbin/killall wpa_supplicant
   
   [Install]
   WantedBy=multi-user.target

   Then activate it:

   sudo systemctl enable wpa_supplicant

For NetworkManager it is enough to mark the connection as automatic:

nmcli connection modify "CONNECTION_NAME" connection.autoconnect yes

6. Security: How to protect your connection

When setting up Wi-Fi via a terminal, it is important to ensure the security of configuration files:

• 🔒 Access rights: File /etc/wpa_supplicant/wpa_supplicant.conf should be accessible only by root:

  sudo chmod 600 /etc/wpa_supplicant/wpa_supplicant.conf

• 🛡️ Use modern standards: Avoid WEP And WPA — set up WPA2-PSK or WPA3. In the config wpa_supplicant please specify:

  proto=RSN
  key_mgmt=WPA-PSK
  pairwise=CCMP

• 🔄 Update your software regularly: Drivers and utilities (eg wpa_supplicant) may contain vulnerabilities. Update them with the command:

  sudo apt update && sudo apt upgrade

• 📛 Hide SSID (optional): If the network should not be visible to everyone, add the following setting to the router configuration hide_ssid=1 and connect with the flag scan_ssid=1 V wpa_supplicant.

Warning: Never store passwords in cleartext in scripts or configuration files with broad access rights. Use wpa_passphrase to generate hashed versions.

FAQ: Frequently Asked Questions

lspci -knn | grep -iA3 net

sudo apt install firmware-b43-installer

deb http://deb.debian.org/debian bookworm main contrib non-free

network={
ssid="NETWORK_NAME"
key_mgmt=NONE
}

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

nmcli device wifi connect "NETWORK_NAME"