How to Fix “Unmanaged Network Interface” Issue in Alma Linux

Managing network connections on Alma Linux systems can sometimes be tricky, especially when encountering issues like an “unmanaged network interface.” In this blog post, we’ll explore a simple solution to this problem using NetworkManager, a popular network management tool in Alma Linux.

Identifying the Issue: You might have come across situations where you try to change the status of a network interface, only to find it set to “unmanaged.” This means you can’t activate or deactivate the interface, which can be frustrating when configuring network connections.

The Solution: Thankfully, there’s a straightforward solution to this problem. By tweaking a few settings in NetworkManager’s configuration file, you can regain control over the network interface.

Step-by-Step Guide:

1. Check Interface Status: Start by checking the status of the network interface using the nmcli -p device command. This will give you an overview of all network interfaces and their management status.
2. Edit NetworkManager Configuration: Open the NetworkManager configuration file located at /etc/NetworkManager/NetworkManager.conf in your favorite text editor.
3. Modify Configuration Settings: Inside the [main] section of the configuration file, add or modify the following lines

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=true

4. Save and Exit: Save your changes to the configuration file and exit the text editor.

5. Restart NetworkManager: To apply the changes, restart the NetworkManager service with the command:

sudo systemctl restart NetworkManager

6. Verify Interface Status: Once NetworkManager restarts, use the nmcli -p device command again to confirm that the network interface is now managed.