Can you have a dynamic Mac address?

In general, the MAC address is tied to a specific piece of hardware and does not change. It is possible, however, under certain circumstances to change the MAC address.

MAC addresses are most often assigned by the manufacturer of a network interface card (NIC) and are stored in its hardware, the card's read-only memory, or some other firmware mechanism. If assigned by the manufacturer, a MAC address usually encodes the manufacturer's registered identification number and may be referred to as the burned-in address. It may also be known as an Ethernet hardware address (EHA), hardware address or physical address.

Although intended to be a permanent and globally unique identification, it is possible to change the MAC address on most modern hardware. Changing MAC addresses is necessary in network virtualization. In this case, the MAC address of the actual NIC is hidden from the network and the network only sees the MAC assigned to the virtual NIC - which can be configured, with some finesse, to be dynamic. It can also be used in the process of exploiting security vulnerabilities. This is called MAC spoofing.