Default Gateway Configuration - Network Not Reachable

Introduction:

Having a properly configured default gateway is crucial for establishing a functional network connection. The default gateway acts as a bridge between the local network and the internet, enabling communication between devices on different networks. However, there are instances where the default gateway is misconfigured or unavailable, leading to a "Network Not Reachable" error. In this blog post, we will explore how to troubleshoot and fix default gateway configuration issues using the nmtui command and verify connectivity with a simple ping test.

Step 1: Access Network Manager Text User Interface (nmtui)

To begin the troubleshooting process, we'll use the nmtui command. Open a terminal or SSH session and enter the following command:

nmtui

This will launch the Network Manager Text User Interface, providing an easy-to-use interface to manage network connections.

Step 2: Edit Connection and Configure the Default Gateway

Within the nmtui interface, navigate to the "Edit a connection" option and select the network connection experiencing the "Network Not Reachable" issue. Typically, this will be your Ethernet or Wi-Fi connection.

Once you've selected the appropriate connection, choose the "Edit" option to modify the connection settings.

Look for the "IPv4" or "IPv6" settings section, depending on your network configuration. In this section, you should find the "Default gateway" field. Ensure that the default gateway IP address is correctly entered. If you're unsure about the correct gateway, consult your network administrator or Internet Service Provider (ISP).

After updating the default gateway, save the changes and exit the nmtui interface.

Step 3: Ping Test to Verify Connectivity

Now that you've reconfigured the default gateway, it's time to verify the network connectivity. We'll use the ping command to check if the network is reachable.

In the terminal or command prompt, enter the following command:

ping 8.8.8.8

The IP address "8.8.8.8" corresponds to Google's public DNS server. A successful ping indicates that your network connection is working, and the "Network Not Reachable" issue has been resolved.

Conclusion:

Configuring the default gateway correctly is vital for establishing network connectivity and accessing the internet. If you encounter a "Network Not Reachable" error, follow the steps outlined in this blog post to troubleshoot and fix the default gateway configuration using the nmtui command. By ensuring the correct default gateway settings, you can enjoy seamless network connectivity and browse the internet without any hindrance.

Remember to consult your network administrator or ISP if you encounter any difficulties or uncertainties during the configuration process.