[libvirt-users] possible to disable but not remove hardware?

I have a situation where I frequently need to "add" and "remove" a NIC, but each time I "add" it, I need the same MAC address. I'm using virt-manager mostly, but would be willing to use "virsh" if necessary, although it doesn't seem to hotplug the same way (something else to figure out another day ;-). It doesn't appear in the domain XML format that there is any "disabled" attribute than can be used. Is that true? Is there a different usage pattern to accomplish this? Thanks, David Mansfield Cobite, INC.