Solving 'No Internet Connection' on Ubuntu Desktop 20.04 LTS: A Comprehensive Guide

Internet connectivity issues can be frustrating, especially on a system as robust as Ubuntu Desktop 20.04 LTS. Whether you're experiencing a wired or wireless connection problem, this guide provides a step-by-step approach to diagnose and resolve common internet connection issues on your Linux system.

1. Check Physical Connections

Firstly, ensure that both your wired and wireless connections are properly established.

For Wired Connections: Verify that the Ethernet cable is securely connected to your computer and your network router.

For Wireless Connections: Make sure that the Wi-Fi switch on your laptop (if applicable) is enabled. Double-check that your device is connected to the correct Wi-Fi network.

2. Check Network Settings

Review the current network settings to ensure a proper configuration.

To view the network icon, look at the top-right corner of your screen. Ensure that you are connected to the desired network and have entered the correct password if applicable.

3. Restart Network Services

Restarting the network services can help resolve connectivity issues.

Open a terminal and run the following command to restart the NetworkManager service:

sudo systemctl restart NetworkManager

4. Check for IP Address

Verify if your device has been assigned a valid IP address.

In the terminal, execute the following command to check for an IP address:

ip a

Look under the inet section for your network interface (e.g., eth0 for wired or wlan0 for wireless). If no IP address is assigned, you can attempt to renew it with:

sudo dhclient -v

5. Check DNS Settings

The DNS resolution can sometimes be the culprit. Test this by pinging an external IP address:

ping 8.8.8.8

If this command works but pinging a website (e.g., ) does not, you may have a DNS issue. Update your DNS settings:

Go to Settings Network in your Ubuntu desktop. Select your connection (Wired or Wi-Fi). Click on the Settings gear icon. Go to the IPv4 tab and change the DNS method to Automatic DHCP. Alternatively, you can enter public DNS like Google DNS (8.8.8.8 and 8.8.4.4).

6. Check Firewall Settings

Ensure that your firewall is not blocking your connection, as this can lead to internet connectivity issues.

To check the status of the firewall, use the following command:

sudo ufw status

If the firewall is active and is suspected to be the cause of the problem, temporarily disable it:

sudo ufw disable

7. Update Network Drivers

Outdated network drivers can sometimes cause connectivity issues. To ensure your drivers are up-to-date:

Update your system with: sudo apt update sudo apt upgrade

8. Reboot Your System

After making changes, reboot your system to ensure all settings are applied and take effect:

sudo reboot

9. Check Router and Modem

Finally, if all else fails, check your router and modem. Restart them and ensure they are functioning correctly.

10. Additional Resources

If the problem persists, consider checking Ubuntu forums or documentation for more specific solutions related to your hardware.

If you have specific error messages or symptoms, feel free to share them for more targeted assistance!