sol3523: Choosing a unique Media Access Control (MAC) address for MAC masquerade

Taken from sol3523: Choosing a unique Media Access Control (MAC) address for MAC masquerade

You can convert the pre-assigned MAC address to a locally administered MAC address by performing the following procedure:

1. Identify the pre-assigned MAC address.
2. Convert the first byte of the address to binary.
3. Change the second to last bit from 0 to 1.
4. Convert the binary value back to hexadecimal.
5. Replace the first byte of the original MAC address with the new hexadecimal value.

Note: A shorthand method to the same result is to add 02h to the first byte of the pre-assigned MAC address.
The following table illustrates the conversion for several addresses:

Pre-assigned MAC address	First byte	Local bit	Flipped local bit	New first byte	Locally administered MAC address
00:01:D7:01:02:03	00	00000000	00000010	02	02:01:D7:01:02:03
01:01:D7:01:02:03	01	00000001	00000011	03	03:01:D7:01:02:03
08:01:D7:01:02:03	08	00001000	00001010	0A	0A:01:D7:01:02:03

 
Note: Even similar MAC addresses will maintain their uniqueness if they are all converted to locally administered