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How to Determine Your Ethernet or
Wireless Hardware Address

This document describes how to determine your device's Ethernet or Wireless hardware address(es). You need to know your hardware address(es) in order to register your computer or printer in the University Host Database.

Contents

  1. What is an Ethernet or Wireless Hardware Address?
  2. The Easiest Way to Discover a Hardware Address

Instructions for some common platforms:

What is an Ethernet or Wireless Hardware Address?

An Ethernet or Wireless hardware address is a number assigned to the hardware interface in (or attached to) your computer or printer. It is assigned by the manufacturer of that Ethernet or Wireless interface, not by UMDNJ. All manufacturers of Ethernet and Wireless interfaces cooperate to ensure that every hardware interface has a unique address.

If your computer has both an Ethernet interface and a Wireless interface, each will have its own unique hardware address.

An Ethernet or Wireless hardware address is a 6-byte hexadecimal number; for example: 0x080007A9B2FC. (Each byte is written as two hexadecimal digits, so there are twelve hexadecimal digits; each hex digit is a number from 0-9 or a letter from A-F. A leading '0x' may be written to make explicit that the following digits should be interpreted as hexadecimal.)

Ethernet and Wireless hardware addresses are often written in other forms, to make them easier to understand. It is common to leave off the leading '0x', and also to separate the six pairs of digits with colons or dashes, like: 08:00:07:A9:B2:FC or 00-00-94-ba-0e-cc. When using colons or dashes to separate the address into six pairs, sometimes any leading zero in each pair of digits is dropped; e.g. 8:0:7:A9:B2:FC or 0:0:94:ba:e:cc. (Note that when dropping leadings zeroes, '00' becomes '0' -- you never completely eliminate any of the six pairs of digits.)

Do not confuse an Ethernet or Wireless hardware address with an Internet Protocol ("IP") address; that's a number assigned to some computers and printers by the UMDNJ, and looks something like: 128.112.1.2 or 140.180.1.2. Your Ethernet or Wireless hardware address is also not your email address, which typically looks something like ( mailto:isthelp@umdnj.edu).

The Easiest Way to Discover a Hardware Address

Often, the fastest way to discover a device's Ethernet or Wireless hardware address is to look for a printed label. For example, if you buy an Ethernet or Wireless interface card, check the box it came in for a label; you may recognize the hardware address on the label. Other times, the actual interface may have a sticky label somewhere on it with the hardware address.

If your computer or printer has a built-in Ethernet or Wireless interface, you may find a label attached to the back or bottom of the computer displaying the hardware address.

If you find a label, make sure it really is a hardware address; the section above describes what an Ethernet or Wireless hardware address looks like. For example, if you see letters of the alphabet other than A-F, you can be sure you're not looking at an Ethernet or Wireless hardware address; perhaps it is a model number or serial number for your computer.

In some cases, you will not find a hardware address displayed on the box, the Ethernet or Wireless interface, or the computer or printer. (Or you may have discarded the box, and opening the computer or printer to examine the interface card inside may not be a good choice.) In these cases, there is usually software you can run on the computer or printer that will display the Ethernet or Wireless hardware address. Instructions for some popular configurations appear below.

Windows 9x, ME

The process of obtaining your ethernet address is fairly simple in Windows 95, Windows 98, and Windows ME. You need to have, at least, installed the Microsoft TCPIP protocol to use this method. If you have installed the MS TCPIP protocol do the following:

  1. Click on Start.
  2. Click on Run.
  3. In the command line box which appears, enter the following and press the “ Enter” key:
  4. Type “winipcfg”
  5. A box will appear with a variety of information. Check the pull-down menu near the top to verify that your Ethernet interface is selected; if it is not, then select it in this menu.
  6. Look for the line labeled Adapter Address . This is your Ethernet interface's hardware address. It will be written out completely as 6 pairs of 2 digits separated by hyphens. Write it down.
  7. Click on the X in the top right-hand corner of the box to close the windows. You are now finished.

Windows 2000, XP

You can find your ethernet address using Microsoft's ipconfig utility:

  1. Click the Start button.
  2. Select Programs and then select Accessories/Command Prompt .
  3. At the C:\> prompt, enter the following then press the Enter key:
  4. Type “ipconfig /all”
  5. Your machine's Ethernet or Wireless hardware address is listed as the Physical Address .
  6. To close the Command Prompt window, enter the following at the C:\> prompt then press the Enter key:
  7. Type “exit”

Mac OS X 10.3, 10.4

To display your Mac's Ethernet or Wireless hardware address:

  1. Make sure that the network interface you're interested in is part of the current location, and is turned "on":
    1. Open the System Preferences application in the Apple menu. (It's also available in the Utilities folder, and sometimes in the Dock.)
    2. Click the Network icon.
    3. In the Location pop-up menu, select a location that includes the network interface of interest. You can verify that a network interface (port) is a member of a location by selecting that location, then in the Show pop-up menu, selecting Network Port Configurations . Verify that network interface of interest appears in the port list, and is turned "on" (its checkbox is checked).
    4. Once you've verified that the network interface you're interested in is part of the current location and is turned "on", you can select Quit System Preferences from the File menu.
    5. If you made any changes in the Network pane in System Preferences that you won't want to retain, make a note of them now, so you can undo them later.
  2. Launch the System Profiler application. This program is normally located in the Utilities folder, which in turn is located in the Applications folder.
  3. In the Contents pane on the left, select Network.
  4. Displayed in the upper-right pane is a list of each of the Mac's network interfaces that are part of the current network location and are turned "on".

Select the item for the Ethernet or Wireless interface in which you are interested.

  1. Displayed in the lower-right pane is information about the selected network interface.

Each interface's hardware address is the value labeled Ethernet address , MAC address, or Hardware (MAC) address This is true even if the device is actually a wireless interface.

  1. Quit the System Profiler application.
  2. If earlier you changed any settings in the Network pane of System Preferences (e.g. to make a particular network interface active) and you wish to change it back, do so now.

PDA Operating Systems

Pocket PC (iPAQ)

  1. Tap on Start and select Settings.
  2. Tap on the System tab on the bottom of the screen.
  3. Tap on the iPAQ WLAN icon.
  4. Tap on the Status button.
  5. The MAC address is listed near the bottom of the screen.

Palm Tungsten C
The MAC address should be listed on the back of the unit under the serial number. If you don't see it, you can obtain the MAC address as follows:

  1. In the Applications launcher, tap on Prefs.
  2. In the Communications section of the Preferences screen, tap on Wi-Fi .
  3. Tap on Info.

For assistance troubleshooting problems with wireless network connectivity, please contact the Technology Service Center at 6-3200, 856-566-6437, or 732-743-3200. Service Center staff will provide further instructions.

You can register for a wireless account at http://istreg.umdnj.edu