LinuxQuestions.org - Change mac address for wlan0 without using macchanger software?

I was not sure if this is the correct subforum or it would be better suited in Networking section, please move mods and sorry if incorrect.

Question
I have running Raspbian on my Raspberry Pi

I have two usb wifi dongles that both work and connect to my router when testing.

- Edimax EW-7811UN
- Adafruit Miniature WiFi (802.11b/g/n)

However when I try to change the Mac Address's of either of these usb devices when only one is plugged in and in use at one time I cannot do it as the effects seem to not take place.

I have tried using cmd

Code:

    ifconfig wlan0 down

    ifconfig wlan0 hw ether 00:00:11:11:00:00

    ifconfig wlan0 up

and also editing /etc/network/interfaces file wlan0 entry

Code:

    iface wlan0 inet static

            hwaddress ether 01:01:01:01:01:01

            address 192.168.1.100

            netmask 255.255.255.0

After doing this and running ifconfig I can see that either of the two USB'S device has the same MAC.

I have also tried rebooting the device but the mac address is the same.

I have heard there is a package called macchanger but I would like to do this without it, how could I go about doing this?