When a browser on your computer needs to grab a web page from a server on the Internet, for example, that request passes down through several layers of the TCP/IP protocol. What MAC Addresses Are Used ForĪt the lowest networking level, network interfaces attached to a network use MAC addresses to communicate with one another. These MAC addresses-sometimes referred to as physical or hardware addresses-are assigned in the factory, but you can usually change the addresses in software. Each network interface connected to your network-whether it’s your router, wireless device, or network card in your computer-has a unique media access control (MAC) address.
