You can detach a network interface from a vRouter by using the virsh detach-device <vm-name> [ --persistent ] <xml-filename> command. However, because the router configuration is independent of hot-plugging, when detaching an interface, the configuration that is associated with this interface remains in the config/config.boot file on the router.

If you attach an interface into the PCI slot that corresponds to the name of an existing interface in the config/config.boot file, then the router reuses the existing configuration by interface name.