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About Your Computer's Ethernet HW Address

*   What is an Ethernet Hardware Address?

The Ethernet hardware address (HW Address) is your Ethernet card's unique identity.

It is a 6-byte hexadecimal number represented by 12 digits (12 digits in hex = 48 bits = 6 bytes).
Each digit must be a number between 0 and 9 or a letter between A and F ( Example: 0040051c0e9f ).
It was permanently assigned and "burnt in" to the card's electronics when it was manufactured and cannot be altered.

An Ethernet card transmits its address with each packet of data, so it acts as a signature or fingerprint of your computer.

It may be referred to as either a hardware address, Ethernet address, NODE ID, adapter address, or MAC (medium access control) address, and might appear as:

*   How do I Find the Ethernet HW Address on Various Operating Systems?

External network adapters and some Ethernet cards will have the HW Address imprinted on them, have a sticker on them with the information, or it will be included in the manual.
NOTE: These strings may omit 0's at the beginning - make sure your HW Address is 12 characters long. If it is not, you need to pad the beginning with 0's. (e.g. Your adapter has 94560e45 printed on it. Your HW address actually is 000094560e45.)

If your card does not have the HW Address on it, or it is already installed in the computer, use the links below to determine the HW Address.

*   Apple Macintosh
*   Windows 2000 and Windows XP
*   UNIX and Linux Operating Systems
*   Networked Printers

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Last Updated:  Friday, November 12, 2010  by  Hostmaster