=== setup: vlan100 on vtnet0 ===
vlan0: flags=808802<BROADCAST,SIMPLEX,MULTICAST,PROXY> metric 0 mtu 1500
	vlan: 100 parent interface: vtnet0
	status: active

=== rename the PARENT (SIOCSIFNAME) ===
vtnet0r
vlan0: flags=808802<BROADCAST,SIMPLEX,MULTICAST,PROXY> metric 0 mtu 1500
	vlan: 0 parent interface: <none>

=== rename back ===
vtnet0
vlan0: flags=808802<BROADCAST,SIMPLEX,MULTICAST,PROXY> metric 0 mtu 1500
	vlan: 0 parent interface: <none>

=== cleanup ===