A MAC address is 6 bytes (48 bits). The first byte contains two special single-bit flags (bits numbered from least significant bit (LSB) upward in each byte):
In hex, common safe first-octet values for locally administered unicast addresses are those where:
Examples (hex): 02, 06, 0A, 0E, 12, 16, 1A, 1E, 22, 26, ... up to FE where the pattern continues. So a spoofed MAC might start 02:11:22:33:44:55. A MAC address is 6 bytes (48 bits)
If you try to set a MAC whose first octet is, for example, 01 (multicast) or 00 (globally unique with LAA=0), some drivers will refuse or silently ignore the change.
Instead of using a random MAC address, force the first octet to a valid locally administered unicast value. In hex, common safe first-octet values for locally
Step-by-step:
Test: This alone will solve the error in 90% of cases. Examples (hex): 02, 06, 0A, 0E, 12, 16, 1A, 1E, 22, 26,
On Windows 10/11:
On macOS:
Now retry your MAC spoofing.