Operation not Permitted on TUN Device?

Silvenga

So I've had this server for a week or two. I connect all my servers to a private virtual network for security. But 3 days ago my OpenVPN tunnel went down to my network. I went to debug and found this:

TUN was working, but then just stopped. This is the error given:

# openvpn --mktun --dev tun0
Fri Jan 10 19:58:53 2014 Note: Cannot open TUN/TAP dev /dev/net/tun: Operation not permitted (errno=1)
Fri Jan 10 19:58:53 2014 Cannot ioctl TUNSETPERSIST(1) tun0: Bad file descriptor (errno=9)
Fri Jan 10 19:58:53 2014 Exiting


TUN is enabled:

# ls -l /dev/net/tun
crw-rw-rwT 1 root root 10, 200 Jan 10 16:45 /dev/net/tun

# cat /dev/net/tun
cat: /dev/net/tun: File descriptor in bad state


I contacted my provider to fix the issue. He reported that he followed these steps on my container:
http://openvz.org/VPN_via_the_TUN/TAP_device

There was no change and the ticket is now categorized under "Server Related Queue".

Is there solution or fix that any has found? And is there a way to figure out if this is my issue or my provider's? Or any other helpful information.

Thanks for any assistance.

petris

Even though tun/tap is enabled in OpenVZ, you can't create persistent devices, which is what you're doing with the command "openvpn --mktun --dev tun0".

Silvenga

@petris

Thanks, but that was only an example, that is not what I am trying to do. The same error is found within the logs of OpenVPN on startup. (I could be wrong but OpenVPN calls that command on startup anyway).

Silvenga

Whoa, fixed by running "rm /dev/net/tun" and re-enable tun. Why does that work?