MAC

A Media Access Control (MAC) address is a hardware address that uniquely identifies each node of a network. A MAC is a 48-bit Address usually represented in hexadecimal format with colons between every 8-bits. For example:  08:00:20:95:fb:83


Each company making an ethernet card is assigned a block of MAC addresses for their cards. A list of companies and their MAC assignments is available here.

To find out your MAC address, choose your operating system:

 
Linux
FreeBSD/OpenBSD/NetBSD
Solaris/NeXTStep		 Windows
Macintosh
Linux
From a terminal on your linux box, as any user, type the following: 
/sbin/ifconfig -a |grep HWaddr
You should see something like the following: 
eth0      Link encap:Ethernet  HWaddr 00:80:5F:CB:52:E7

FreeBSD/OpenBSD/NetBSD
From a terminal on your BSD box, as any user, type the following:

/sbin/ifconfig -a |grep ether
You should see something like the following: 
        ether 00:d0:b7:bb:6f:f5

Solaris/NeXTStep
From a terminal on your Solaris/NeXTStep box, as root, type the following:

/sbin/ifconfig -a |grep ether
You should see something like the following: 
        ether 00:d0:b7:bb:6f:f5
 

Windows
Start a Command Prompt
In the Command Prompt, type the following:

ipconfig /all
You should see something like the following: 
Windows NT IP Configuration

        Host Name . . . . . . . . . : example.math.ias.edu
        DNS Servers . . . . . . . . : 192.108.106.49
                                      192.16.204.20
        Node Type . . . . . . . . . : Hybrid
        NetBIOS Scope ID. . . . . . :
        IP Routing Enabled. . . . . : No
        WINS Proxy Enabled. . . . . : No
        NetBIOS Resolution Uses DNS : Yes

Ethernet adapter N1001:

        Description . . . . . . . . : Adapter Name Here
        Physical Address. . . . . . : 00-08-C7-82-4A-7E
        DHCP Enabled. . . . . . . . : No
        IP Address. . . . . . . . . : 192.168.192.253
        Subnet Mask . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . : 192.168.192.254
        Primary WINS Server . . . . : 192.168.192.252

The MAC Address is called the Physical Address. Make sure you use the Physical Address from the correct adapter, check the line that say's Adapter Name Here to see if it looks reasonable. Do NOT use the PPP Adapter

Macintosh

(OS 10.1 and higher) Systems

Wired Connection

  1. From the dock, select System Preferences.
  2. Select the Network applet.
  3. Next to Show, make sure Built-in Ethernet is selected. Click "Advanced" at the bottom of the page.
  4. With the Ethernet tab selected, the Ethernet ID will look something like the following: 00:16:cb:a8:bc:46

Wireless Connection

  1. From the dock, select System Preferences.
  2. Select the Network applet.
  3. Select AirPort from the side bar, and select "Advanced" from the bottom
  4. At the bottom of that page you will see AirPort ID.

If there are errors or ommisions in this document, please send comments/corrections to help@math.ias.edu. Thank you