The IANA will assign unicast global IEEE 802 MAC address from it's assigned OUI (i.e., 00-00-5E) for use in IETF standard track protocols. The intended usage is for dynamic mapping between IP addresses and IEEE 802 MAC addresses. These IEEE 802 MAC addresses are not to be permanently assigned to any hardware interface, nor is this a substitute for a network equipment supplier getting its own OUI. Thanks. IANA