How to install tun/tap driver for openvpn on centos linux?

Question

How to install tun/tap driver for openvpn on centos linux?

Best wishes for you.

Answer 1

The TUN/TAP driver is already part of the standard kernel image. Just run modprobe tun to load it.

If you are inside a virtual server (e. g. OpenVZ/Virtuozzo, Linux-Vserver et al) the provider needs to enable tun/tap-functionality first since you cannot load kernel modules yourself in these environments.

Answer 2

The standard kernel image has TUN/TAP driver configured as default. But if you want to check that with your running kernel you can:

$ sudo apt-get install linux-headers-`uname -r`
$ cd /usr/src/linux-headers-`uname -r`
$ sudo make menuconfig

After searching for "TUN" you will find:

Symbol: TUN[=m]
│ Prompt: Universal TUN/TAP device driver support
│   Defined at drivers/net/Kconfig:112
│   Depends on: NETDEVICES
│   Location:
│     -> Device Drivers
│       -> Network device support (NETDEVICES [=y])
│   Selects: CRC32 

The kernel module is located at:

$ ls /lib/modules/`uname -r`/kernel/drivers/net/tun.ko

You can repeat almost the same procedure with a kernel source to check if TUN driver is compiled as a module. Just replace the first two commands with:

$ tar xvjf linux-2.6.XX.X.tar.bz2 && cd linux-2.6.XX.X

and continue.

Best regards

Humber