2.1.6 Configuration of Darwin (MacOS/X) kernels

Tinc on Darwin relies on a tunnel driver for its data acquisition from the kernel. OS X version 10.6.8 and later have a built-in tun driver called "utun". Tinc also supports the driver from http://tuntaposx.sourceforge.net/, which supports both tun and tap style devices,

By default, tinc expects the tuntaposx driver to be installed. To use the utun driver, set add ‘Device = utunX’ to tinc.conf, where X is the desired number for the utun interface. You can also omit the number, in which case the first free number will be chosen.