Wifi Not Working in Linux Here is How to Fix

Diagnosing the Issue

When Wi-Fi is not working in Linux, the first step is to determine whether the problem is hardware or software related. Here’s how you can diagnose the issue:

Check Hardware Functionality: Open a terminal and run the command ping localhost. If the ping is successful, it indicates that your hardware is functioning correctly. If not, you may have a hardware issue.
Check Network Interface: Run the command ip addr to see if your system detects an active network interface. Look for labels such as “wlp0s1” which indicate a wireless network interface.

Installing Drivers

If your Linux distribution is not detecting your Wi-Fi network, you may need to install or reinstall the Wi-Fi drivers.

Using the Ubuntu ISO: If you are using Ubuntu, you can install drivers from the Ubuntu ISO file. Download the ISO corresponding to your Ubuntu version and mount it to a virtual drive using the following commands:
```
sudo mkdir /media/cdrom
sudo mount -o loop ~/Downloads/ubuntu-*.iso /media/cdrom
```
Then, go to “Software Updater,” click on “Settings,” and select the “Additional Drivers” tab to install the wireless network adapter drivers.
Broadcom Wireless Cards: For Broadcom wireless cards, you need to install specific drivers. Identify your Broadcom card using lspci and then follow instructions from resources like Ask Ubuntu to install the necessary firmware and drivers.

Common Issues and Fixes

Device Not Detected

If your wireless device is not detected, follow these steps:

List USB Devices: Run sudo lsusb to list all USB devices. Look for lines containing “Wireless Adapter” or “RTL”.
List PCI Devices: Run sudo lspci to list PCI devices. Look for lines containing “Network Controller” or “Ethernet Controller”.
Find Driver Module: Use sudo lshw -C network | grep "driver" to find the exact driver module your wireless device is using.

Driver Module Missing

If the driver module is missing, you need to install it. Here are some commands for different distributions:

Debian/Ubuntu: sudo apt install network-manager.
Fedora: sudo dnf install NetworkManager.
Arch Linux: sudo pacman -Syu networkmanager.

DNS Issues

If you are experiencing DNS issues, try changing the DNS resolvers on your router to Google's or OpenNIC's servers. This can resolve page load errors if all devices on your network are affected.

No Network Manager

If the Network Manager is not installed or not working, you need to install it. Use the commands mentioned above for your specific distribution.

Additional Troubleshooting Steps

Disable IPv6: Sometimes, disabling IPv6 can resolve Wi-Fi connectivity issues. Check if IPv6 is enabled and disable it if necessary.
Check for Firmware Issues: For Intel Wi-Fi cards, issues with firmware can cause connectivity problems. Ensure that the firmware is up to date and try removing or updating specific firmware files if necessary.
Reboot and Power Cycle: Rebooting your system and power cycling your router can sometimes resolve connectivity issues. Also, ensure that your system is fully powered down before switching from another operating system like Windows.

Connecting to the Internet Without Wi-Fi

If you cannot connect to Wi-Fi, you need an alternative method to install drivers:

Wired Connection: Connect to a wired network using an Ethernet cable and install the necessary drivers.
USB Tethering: Use a smartphone to tether your internet connection via USB or Bluetooth.
Download Drivers on Another System: Download the DEB files of the drivers on another system and transfer them to your Linux machine via USB.

By following these steps, you should be able to diagnose and fix most common Wi-Fi issues in Linux.