The MAC address or MAC Address (media access control address) of a device is a unique identifier that is assigned to network interfaces. Wireless network cards or Ethernet network cards, routers, printers, etc., all have their own 48-bit identifier that is not repeated throughout the world, it is like their own fingerprint to communicate. In a computer network, computers can be identified through their IP address, but they can also be identified by their MAC Address.
Manufacturers often add this identifier when devices are manufactured, and it is usually stored in the hardware’s ROM (read-only memory), or in some other firmware mechanism. For this reason, it is impossible to modify it since it is in a read-only area that cannot be altered. In addition, there is also a regulatory entity that is in charge of providing the standards by which MAC addresses are assigned, this is the Institute of Electrical and Electronic Engineering.
WHAT IS THE MAC ADDRESS FOR?
Understanding that the MAC address is a unique identifier for all network devices, we know that any device that has hardware that allows it to connect to a network has its own MAC Address. Computers, cell phones, tablets, routers, printers, switches, etc. Everyone has their own address.
One of the most common uses that users give to MAC Addresses is to restrict access to a network. Many have probably had their first contact with this term when they decided to delve into the configuration of their routers. We can use the MAC address to allow or restrict access to only certain devices. It is a good way to ensure the security of your network if you only authorize the MAC addresses of your own computers and do not allow the connection of any unknown MAC Address.
The MAC Address can also be used to obtain the location of a device through GPS, which can allow tracking of the movements of a person, and has much higher precision than geopositioning through IP. If we have the WiFi on and we approach a router, we are immediately leaving our MAC Address in its registry.
CAN THE MAC ADDRESS BE HIDDEN OR CHANGED?
As we mentioned before, the MAC Address goes in read-only memory and cannot be altered, but it can be masked or hidden. The MAC spoofing or MAC Souplantation is a technique to “change the MAC address” into believing the operating system to have a different one. By doing this you can change the identity of a device for whatever reason. For example, when we connect to a public WiFi network we can prevent a malicious user from cloning our MAC address and commenting on a crime by using the identifier of our computer, and “leaving us dead.”
We can also bypass access control lists on servers or routers if we change our MAC Address, supplanting the address of another authorized device or simply using a new one that is not among those blocked. Clearly, these types of practices can be used for both legal and illegal purposes.