How to identify the manufacturer of your network device using its mac address
What is MAC address ?
In computer networking a MAC address (also known as an Ethernet Hardware Address or physical address) is an unique identifier consisting of six groups of two hexadecimal digits. An example of a MAC address would be 00:1E:C1:4C:E6:C6. It is 48 bits long, which means that there are 281,474,976,710,656 possible MAC addresses. According to IEEE the 48-bit range of addresses will be exhausted no sooner than the year 2100, but when this happens, they will most likely be replaced by new 64-bit addresses.
MAC addresses are used by many different Layer 2 technologies, including Ethernet, Token Ring, 802.11, Bluetooth, FDDI or Fibre Channel. In IEEE 802 networks, Layer 2 is the Data Link Layer, which is composed of of two sublayers – the Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. The MAC sublayer is responsible for managing the data traveling over the network. It also interfaces directly with the network medium. In today’s TCP/IP networks, a MAC address can be converted to a higher level address, such as an IP address, by ARP ( or Address Resolution Protocol ) with the only difference that IP addresses function at layer 3 in the OSI model.
A MAC address must be assigned to every network device, that connects to a network. Usually MAC addresses are programmed into hardware by the device manufacturer during the manufacturing process. For this reason, MAC addresses are always the same regardless of the software managing the device. But although intended to be permanent, it is possible to change the MAC address on most of today’s network devices, using special software or using a few Windows tricks.
The first three bytes of the above example (00:1E:C1) contain the ID number of the adapter manufacturer, in this case 3Com. These first three bytes are assigned by the IEEE and the database is available online at IEEE OUI and Company_id Assignments website, where you can easily identify the manufacturer of your network hardware. The second half of a MAC address represents the serial number of the adapter, assigned by the manufacturer.
