What is MAC Address?
MAC, Media Access Control,
address is a globally unique identifier assigned to network devices, and
therefore it is often referred to as hardware or physical address. MAC
addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS
format. The first 3-bytes are ID number of the manufacturer, which is assigned
by an Internet standards body. The second 3-bytes are serial number assigned
by the manufacturer.
MAC layer represents layer 2 of the TCP/IP (adopted
from OSI Reference Model), where IP represents layer 3. MAC address can be
thought of as supporting hardware implementation whereas IP address supports
software implementation. MAC addresses are permanently burned into hardware
by hardware manufacturer, but IP addresses are assigned to the network devices
by a network adminstrator. DHCP relies on MAC address
to assign IP addresses to network devices.
How do I find a MAC address of network device?
Operating Systems support various command-line and GUI utilities to allow
users to find MAC address of the system. On Unix variants including Solaris
and Linux support "ifconfig -a", "ip link list" or "ip address show" command that displays MAC address of the
network device among other useful information. Windows including NT, 2000,
XP and 2003 support "ipconfig /all" command that displays MAC address. On
a MacOS, one can find MAC address by opening "System Preferences", then