Change MAC address

A MAC address identifies the device connected to a network and allows the network to track, restrict or allow access based on it. Routers identify and assign static IP addresses based on the MAC addresses of devices. Before you try to change the MAC address, you need to know the value that you want to use.

Set the 2’s place bit (the “locally administered” bit) in the first byte, to differentiate it from a guaranteed globally unique MAC address. Usually the first three bytes an unicast MAC address is an “Organizationally Unique Identifier” (OUI) that the IEEE assigned to the manufacturer of your Ethernet device. Manufacturers are required to make sure they keep the last 3 bytes unique.

Avoiding all of that knowledge, the MAC address generator tool can generate a valid address for you.

If a specific MAC address, like 00:0a:95:9d:68:16, is required:

$ sudo ifconfig en0 00:0a:95:9d:68:16

To randomly generate new MAC address and assign it to en0 network interface:

$ openssl rand –hex6 | sed ‘s/(..)/1:/g; s/.$//’ | xargs sudo ifconfig en0 ether

When you restart your Mac computer, the Mac address reverts to the default.