`tunctl` is provided by `uml_utilities` package for "User Mode Linux", which is a long-dead-since-year-2007 project. Some distros (e.g. Arch Linux) have dropped support for `uml_utilities` years ago (Arch Linux dropped it in May 2013: https://lists.archlinux.org/pipermail/aur-general/2013-May/023611.html). One should now use `ip tuntap` provided by `iproute2` package on modern distros. Signed-off-by: Sergey Matveev <stargrave@stargrave.org>