“Cloning MAC Addresses” Whitepaper – “At one time or another, you may find it useful to have two machines with the same physical network address. This is how it is done.” In .pdf format.
You can download it from the following link: https://packetstormsecurity.com/files/download/14911/mac_address_cloning.pdf
Source: https://packetstormsecurity.com/files/14911/mac_address_cloning.pdf.html