OpenVPN ERROR: Cannot open TUN/TAP dev /dev/net/tun: No such file or directory

[sunmast]

Hi,

Today I'm setting up my RT-N66W router as a openvpn client from start up script. When testing the simplest static key configuration, I encountered this error:

wei@RT-N66W:/jffs/vpn# openvpn dy.conf
Sun Mar 13 21:57:05 2016 OpenVPN 2.3.8 mipsel-unknown-linux-gnu [SSL (OpenSSL)] [LZO] [EPOLL] [MH] [IPv6] built on Dec 24 2015
Sun Mar 13 21:57:05 2016 library versions: OpenSSL 1.0.2e 3 Dec 2015, LZO 2.08
Sun Mar 13 21:57:05 2016 WARNING: file 'static.key' is group or others accessible
Sun Mar 13 21:57:05 2016 ERROR: Cannot open TUN/TAP dev /dev/net/tun: No such file or directory (errno=2)
Sun Mar 13 21:57:05 2016 Exiting due to fatal error

I was using the same configuration which was used on a Ubuntu server which works fine for years, but here it complains cannot open TUN/TAP devices.

Any ideals? Thanks!

 

[RMerlin]

As the error says, you are missing the tun interface. This is automatically created by the router if you use its built-in OpenVPN support - there's little reason for you to manually do everything. But if you must:

modprobe tun
openvpn --mktun --dev tun1