The Ethernet Hardware (MAC) Address
MAC addresses have nothing specifically to do with Apple Macintosh or MacOS computers, although most Apple Macs will have a MAC as described below.
A media access control (MAC) address is a unique number associated to an ethernet card, by the card vendor. Proper communication on any subnet requires that each networked host interface have a unique MAC. In general, it will be unique over an entire large site such as a University and is thus useful for uniquely identifying a typical computer.
The MAC address is generally presented in one of 3 ways, as shown in the examples below:
- colon-delimited (typical Unix style)
09:00:07:A9:B2:EB
- dash-delimited (Windows style)
09-10-4A-B9-E2-A4
- non delimited:
080007A92BFC
The numbers are hexadecimal, meaning they cover the range of decimal values 0 to 15 and are represented by members of the set { 0123456789ABCDEF }
.
Determining the MAC Address of Your Computer
MS Windows
- In the search bar type:
cmd
- A DOS-like text command shell will then appear, into which you type:
ipconfig /all
- The number to the right of Physical Address is your MAC address.
Linux
On Linux systems, the ethernet device is typically called eth0. If you are not logged in as the root user, you will need to use the full path to the ifconfig command.
# /sbin/ifconfig -a
user@host$ /sbin/ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:0A:E6:98:92:e1
inet addr:128.100.75.247 Bcast:128.100.75.255 Mask:255.255.255.0
inet6 addr: fe80::20a:e6ff:fe98:92e1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:50778673 errors:0 dropped:0 overruns:0 frame:0
TX packets:27025350 errors:0 dropped:1 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:214857179 (204.9 MiB) TX bytes:3309712747 (3.0 GiB)
Interrupt:19 Base address:0xd400
The MAC address is the HWaddr entry on the line beginning with eth0.
MacOS
- From the dock, select "System Preferences".
- Select the "Network" Pane
- With the TCP/IP tab selected, the number next to Ethernet Address is the MAC address.