To add a new virtual network interface for a VM, we can open the network device dialog using the Add button from the Hardware tab of the VM:

The dialog box for creating vNICs is similar to the network dialog box that we learned about in Chapter 6, KVM Virtual Machines, in the Creating a KVM section. To remove a vNIC, simply select the network device and click on the Remove button. 

If the Hotplug option for the network interface is enabled for the VM, we can add or remove the network interface without powering down the VM. The following screenshot shows the Hotplug option for KVM VMs: