The existing FAQ describes getting the 'tuntap' driver required for aiccu for OSX either through 'brew', or 'tuntaposx'. However, this information now needs some qualification: Starting with OSX Yosemite, unsigned kernel extensions won't run by default. This restriction will prevent the homebrew compiled tuntap from loading in Yosemite (and apparently this problem isn't going away for homebrew self-compiled kexts.) Unless one is going to disable the signed kext security feature, a signed tuntap binary is required in newer versions of OSX. Tuntaposx, starting with version 20141104, has a signed kext binary. However, if you install an older version -- or had installed an older version, and then upgraded to Yosemite -- it won't work. If you experience any tuntap loading problems once on Yosemite, make sure you attempting to run a signed tuntap kext.