new-mac-address.sh

if [ ! -f .ORIGINAL_MAC_ADDRESS ]; then
  ifconfig en0 | grep ether | cut -d' ' -f2 > .ORIGINAL_MAC_ADDRESS
  echo "Backup of original MAC address saved in .ORIGINAL_MAC_ADDRESS"
fi

if [[ -z "$1" ]]; then
  echo "Usage: ./new-mac-address.sh [generate|reset]"
  exit 0
fi


if [[ "$1" = "generate" ]]; then
  MAC=da:`openssl rand -hex 5 | sed 's/\(..\)/\1:/g; s/.$//'`
elif [[ "$1" = "reset" ]]; then
  MAC=`cat .ORIGINAL_MAC_ADDRESS`
else
  echo "Unknown command: $1"
  exit 0
fi

echo "Changing the MAC to $MAC. You may be asked for a root password."

sudo ifconfig en0 ether $MAC

How to use this script:

To generate a new mac address, run

 ./new-mac-address.sh generate

This will save a .ORIGINAL_MAC_ADDRESS file in the current directory. Then, to restore your old mac address, run

./new-mac-address.sh reset

Restoring the original mac address isn't strictly needed, but can be helpful if you have external devices (e.g. other wifi routers) that have your mac address stored.