Click on Apple Menu (usually on top left corner), and click System Preferences.The Physical Address should be in format M:M:M:S:S:S. And locate for the 'Physical Address' or 'HWaddr' field.In Command Prompt, type ipconfig/all and press Enter.To find MAC Address, see the instructions given below for popular operating systems. It may be interesting for you to know that all the OUIs are registered and assigned to the manufacturers by IEEE. For example, let's say a network card manufactured by dell has a physical address: 00-14-22-04-25-37, in this address, 00-14-22 is the OUI of Dell which identifies that the device is by Dell. OUI is always the same for NICs manufactured by the same company. The first three sets of two hexadecimal numbers in a MAC Address identifies the card manufacturer, and this number is called OUI (organizationally unique identifier).

There are several NIC manufacturers some well-known of them are Dell, Cisco, Belkin. The physical address is stored into the NIC by its manufacturer, that is why this address is also called a burned-in address (BIA) or ethernet hardware address. The network adapters or network interface cards always come with a MAC address which is fed into hardware, usually in read-only memory (ROM), or BIOS system. MAC Address usually consists of six groups of two hexadecimal digits. It identifies the hardware manufacturer and is used for network communication between devices in a network segment. It is also known as a physical or hardware address. MAC Address or media access control address is a unique ID assigned to network interface cards (NICs). All this information is useful if you want to verify the generated mac address with the original vendor of this device in OUI vendor database. Finding the mac address from this database tells us which manufacturer originally manufactured this device and what is the prefix, postfix of a given mac address, moreover it tells us what country was this device manufactured. The MAC Address vendor database consists of a list of mac addresses of all devices manufactured till date. MAC Address Lookup Tool searches your MAC Address or OUI in mac address vendor database.

Mac serial number model