Why Ubuntu Can't Detect WiFi: Troubleshooting Drivers and Adapters

The situation when after installing the operating system Ubuntu Finding a missing wireless network icon is one of the most common and annoying problems for Linux newbies. Unlike Windows, where hardware manufacturers often provide drivers on disk or they are integrated by the motherboard manufacturer, in the world of open source software, the situation with hardware support can be more complex. Often, the cause is the absence of proprietary (closed) modules that cannot be distributed with the distribution for licensing reasons.

However, it's too early to panic: in most cases, the adapter is physically functional, and the system detects it, but simply cannot start it without additional software code. NetworkManager, the standard network management tool, simply isn't receiving accurate data from the system kernel about the device's status. You'll need to run diagnostics via the terminal to determine whether the adapter is software-locked or missing firmware.

In this guide, we'll detail the steps to restore your wireless connection. We'll cover driver installation methods and using the utility. rfkill To remove blocks and manually configure configuration files, it's important to understand that the solution often depends on the specific chipset of your network card.

Equipment diagnostics via terminal

The first step should always be accurate device identification. The graphical interface may be silent, but the command line will tell the whole truth about what the system sees at the PCI or USB bus level. First, you need to determine the model of your network adapter, as this will determine the driver selection.

Enter the command lspci for internal cards or lsusb For USB dongles. In the output, look for lines containing the words "Wireless," "Network," "802.11," or manufacturer names like Broadcom, Realtek, Intel, Qualcomm AtherosIf the device shows up here, it means there is physical contact and the problem is purely software-related.

Next, check whether the Linux kernel sees the network interface itself. The command ip link show or older ifconfig -a will show a list of all interfaces. Wireless adapters are usually referred to as wlan0, wlp2s0 or similar. If the interface is there, but it is in a state DOWN, you can try to lift it manually.

The key is to check the status of the locks. Utility rfkill controls radio modules. Enter the command:

rfkill list all

In response, you'll see a list of devices labeled "Soft blocked" (software blocking) and "Hard blocked" (hardware blocking via a switch on the case). If the device is labeled "Hard blocked: yes," no terminal commands will help—you'll need to look for a physical slider on the laptop or a key combination. Fn + F-key with an antenna icon.

⚠️ Note: If rfkill shows "Soft blocked: yes," this is often due to a conflict with Windows' airplane mode when dual-booting. Windows may "power off" the device before shutting down, and Linux inherits this state.

Installing proprietary drivers

The most common reason why Ubuntu The problem is that the WiFi isn't working, which is due to the lack of drivers for the chips. Broadcom and some models RealtekFortunately, Ubuntu's repositories have an automatic mechanism for finding and installing such drivers, but it requires... internet access. This creates a vicious circle: the driver needs the internet, and the driver needs the internet.

There are three ways to resolve this issue: connect via an Ethernet cable, share your phone's internet connection via a USB modem (RNDIS mode), or download the DEB packages on another computer. Once you have internet access, open the "Software & Updates" app. Go to the "Additional Drivers" tab.

The system will scan and offer available options. For Broadcom, this is usually a package bcmwl-kernel-sourceFor others, specific modules are required. Select the recommended option and click "Apply Changes." The process will take a few minutes, after which a reboot will be required.

If the graphical interface doesn't work or you prefer the terminal, use the package manager. apt. First, update the database:

sudo apt update
sudo apt install bcmwl-kernel-source

Some older Broadcom cards may require a package firmware-b43-installerIt's important not to mix up the drivers: installing the wrong module can lead to conflicts and the complete disappearance of the interface. Always uninstall previously installed, faulty drivers before installing new ones.

Problems with Realtek drivers and manual compilation

Adapters from Realtek, especially new models that support the standard AC And AX (Wi-Fi 6) often don't have drivers in the standard Linux kernel. In such cases, standard installation methods are available via apt don't work and require manual compilation from source code. This is a more complex approach, requiring the installation of developer tools.

You need to install the packages first build-essential, git and kernel header files (linux-headers-generic). Then you need to find a repository with a driver for your chipset (for example, rtl8812au, rtl8821ce) on GitHub. The process typically involves cloning the repository, creating a module directory, and running the installation script.

Approximate sequence of actions for a popular chip rtl8821ce:

sudo apt install git dkms build-essential
git clone https://github.com/tomaspinho/rtl8821ce.git
cd rtl8821ce
chmod +x dkms-install.sh
sudo ./dkms-install.sh

Once the script completes, the module will be built specifically for your kernel version and registered in the system. If the Linux kernel is updated (which happens regularly in Ubuntu), this driver may break, and you'll have to repeat the process or use DKMS for automatic rebuilding.

What is DKMS and why is it needed?

Dynamic Kernel Module Support (DKMS) is a framework that allows for automatic rebuilding of third-party kernel modules (drivers) when updating the operating system itself. Without DKMS, you would have to manually compile the WiFi driver after each Ubuntu kernel update.

NetworkManager Configuration Management

Even with the drivers installed, configuration conflicts may occur. In Ubuntu, the network connection service is responsible for NetworkManagerSometimes it freezes or saves incorrect settings, especially if you frequently switch between different networks or use virtual machines.

You can check the service status with the command systemctl status NetworkManagerIf the service is not active, start it through sudo systemctl start NetworkManagerTo completely reset your network settings, you can delete the connection configuration files (but be careful, this will delete saved WiFi passwords):

sudo rm /etc/NetworkManager/system-connections/*

It is also worth paying attention to the configuration file /etc/NetworkManager/NetworkManager.confIn some cases, adding a line managed=true to the section [ifupdown] helps the system take over control of the interface if it was previously controlled by another service.

Another common issue is aggressive power saving. Linux may attempt to conserve power by disabling the WiFi adapter, which results in connection drops or failure to connect. You can disable this by creating a configuration file:

sudo nano /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf

Change the value wifi.powersave on 2 (which means disabling power saving). This often solves the problem of an unstable signal.

⚠️ Note: NetworkManager configuration interfaces may vary depending on the Ubuntu version and desktop environment used (GNOME, KDE, XFCE). In newer versions, settings may be hidden deeper in the menu.

Kernel conflicts and system updates

Sometimes the problem isn't a missing driver, but rather that the current Linux kernel has a bug or is incompatible with your hardware. This often happens immediately after a major system update, when a new kernel version is installed and the drivers haven't yet been optimized.

In this case, rolling back to a previous version helps. When booting the computer, hold down the key Shift (or Esc) to bring up the bootloader menu GRUBSelect "Advanced options for Ubuntu" and boot with the kernel marked "(recovery mode)" or simply an older version.

If WiFi works with the old version, the problem is with the new kernel. You can either temporarily stick with the old version or try a full system update, as driver patches are often delayed. The command sudo apt full-upgrade may resolve the issue by making the necessary corrections.

It's also worth checking the system logs for firmware-related errors. Command dmesg | grep firmware will show which specific microcode files failed to load. This will give the exact file name that needs to be found and placed in the directory. /lib/firmware.

Laptop specifics and dual booting

Laptop owners often encounter unique issues related to power management and hardware switches. As mentioned earlier, Windows in Fast Startup mode doesn't completely shut down the computer, but instead puts it into hibernation, blocking the hardware. This is a common reason why Ubuntu doesn't detect WiFi after rebooting from Windows.

To resolve this issue, disable Fast Startup in Windows. Go to "Control Panel" -> "Power Options" -> "Choose what the power buttons do" and uncheck "Turn on fast startup." Then, perform a full shutdown (not a restart) and then turn on your computer.

Additionally, some laptops (e.g., HP, Lenovo) require entering special commands in the BIOS/UEFI to activate the wireless module if it was blocked at the firmware level. Also, check that airplane mode isn't enabled in the BIOS.

If nothing helps, you can try to manually unlock the device via the terminal using the command sudo rfkill unblock allIn rare cases, physically removing the battery (if it's removable) for 10-15 seconds can help to discharge the static charge and the controller's state.

Why did WiFi disappear after updating Ubuntu?

An update often includes a new version of the Linux kernel. Drivers, especially proprietary or manually compiled ones (DKMS), may not have time to update or configure themselves automatically for the new kernel. Solution: boot into the old kernel via GRUB and run sudo apt update && sudo apt upgradeto install the missing modules.

How can I find out the exact model of my WiFi adapter without internet access?

Use the command lspci -nn (for internal cards) or lsusb (for USB). Find the line with "Network controller" or "Wireless." You can enter the vendor_code and device_code (e.g., [14e4:4365]) into your phone's search engine to find the exact chipset name and the required driver.

Is it possible to use a USB WiFi adapter as a temporary solution?

Yes, but proceed with caution. Cheap adapters with Realtek chips often require manual driver installation, which is difficult without internet access. It's better to look for adapters with Atheros chips or those marked as "Compatible with Linux" (they work out of the box). However, if you have the ability to share your phone's internet connection via USB, this will be a more stable temporary solution for installing the primary adapter's drivers.