By default, static MAC addresses have the VMware Organizationally Unique Identifier (OUI) as the prefix. However, the range of free address provided by the VMware OUI is restrictions.
If you choose to use the VMware OUI, part of the range is reserved for use by vCenter Server, host physical NICs, virtual NICs, and for future use.
You can set a static MAC address that contains the VMware OUI prefix in compliance with the following format:
where XX is a valid hexadecimal number between 00 and 3F, and YY and ZZ are valid hexadecimal numbers between 00 and FF. To avoid conflict with MAC addresses that are generated by vCenter Server or are assigned to VMkernel adapters for infrastructure traffic, the value for XX must not be greater than 3F.
The maximum value for a manually generated MAC address is as follows.
To avoid conflicts between the generated MAC addresses and the manually assigned ones, select a unique value for XX:YY:ZZ from your hard-coded addresses.