who assigns the first six digits of the mac address
MAC address MAC addresses are most often assigned by the manufacturer of a network interface controller (NIC) and are stored in its hardware, such as the card's read-only memory or some other firmware mechanism. If assigned by the manufacturer, a MAC address usually encodes the manufacturer's registered identification number and may be referred to as the burned-in address (BIA). It may also be known as an Ethernet hardware address (EHA), hardware address or physical address (not to be confused with a memory physical address). This can be contrasted to a programmed address, where the host device issues commands to the NIC to use an arbitrary address.
Address Verification System The Address Verification System (AVS) is a system used to verify the address of a person claiming to own a credit card.[1] The system will check the billing address of the credit card provided by the user with the address on file at the credit card company. The other security features for the credit card include the CVV2 number.