Download the plunderbug.sh script for *nix platforms from the Hak5 Download Center.
Open a terminal, change to the directory of the downloaded plunderbug.sh script, make it executable (chmod +x ./plunderbug.sh) and run it as root.
plunderbug.sh accepts the arguments --mute and --unmute to switch between active and passive modes
If preferred, the Plunder Bug can be muted and unmuted by opening Network from System Preferences. Click Advanced, then select "Off" from the Configure IPv4 and IPv6 menus, then click OK and Apply.