Why can't I spoof my wifi card's MAC address to
1F:2E:3D:4C:5B:6A. Is that address invalid?
root@:~# ifconfig wlan0 down root@:~# ifconfig wlan0 hw ether 1f:2e:3d:4c:5b:6a SIOCSIFHWADDR: Cannot assign requested address
As explained in this AskUbuntu question/answer, a unicast MAC address' first octet (your
1f) has to be even.
1f (31) is not even, you can't assign it.