The virbr0 interface is a virtual network interface that is created by the Linux KVM (Kernel-based Virtual Machine) virtualization system. It is used to provide Network Address Translation (NAT) for virtual machines, allowing them to connect to the internet or other networks.
To disable the virbr0 NAT interface, you will need to modify the configuration of the virtualization system. Here are the general steps to do this:
Stop the virtualization system: Depending on your Linux distribution and the virtualization system you are using, you may need to stop the virtualization service or daemon in order to make configuration changes. For example, you may need to run the "systemctl stop libvirtd" command to stop the libvirt daemon.
Edit the virtualization configuration: The configuration for the virtualization system is usually stored in a configuration file or a set of configuration files. To disable the virbr0 NAT interface, you will need to locate the relevant configuration file and edit it to remove the NAT configuration for virbr0.
Restart the virtualization system: After making the necessary changes to the configuration, you will need to restart the virtualization service or daemon to apply the changes. For example, you may need to run the "systemctl start libvirtd" command to restart the libvirt daemon.
Test the configuration: After making the changes, you should test the configuration to ensure that the virbr0 NAT interface has been disabled as expected. You can do this by attempting to connect to the internet or another network from a virtual machine, or by checking the output of the "ip a" command to verify that the virbr0 interface is not present.
It is generally a good idea to make a backup of your virtualization configuration before making any changes, in case you need to restore it later. If you encounter any problems while disabling the virbr0 NAT interface, you may need to seek help from the Linux KVM community or your Linux distribution's support resources.