ERROR(BTap): DeviceIoControl(TAP_IOCTL_GET_MTU) failed about badvpn HOT 14 CLOSED

On Tuesday, September 30, 2014 at 22:25, Oskar Liljeblad wrote:

It is true that you cannot set the MTU, but this code is getting it. This
is the first time I'm seeing this error, and I've tested this on different
WinXP and Win7 machines.

I suspect this is a problem on your end. Perhaps a permission issue, but
seems unlikely considering that opening the device succeeds.

Or maybe the most recent version of the tap-windows driver broke it? You
can try older OpenVPN builds.

Yes, you're right, it must be an issue on my computer - I tried badvpn on
another one and was not able to reproduce the issue.

On the computer with the problem I have two TAP NICs, but that should not
make a difference, should it? Both computers are Windows 8.1 by the way.

Strange, the "DeviceIoControl(TAP_IOCTL_GET_MTU) failed" problem is reproducable
on my work computer. I tried the usual: reboot, run as administrator, etc.
I tried precompiled badvpn-1.999.128-win32 and I compiled the code on my own

• same issue. This is Windows 8.1 (6.3/build 9600) (64bit) with TAP drivers
  from OpenVPN 2.3.4-I603 (also 64bit).

NOTICE(tun2socks): initializing BadVPN tun2socks 1.999.128
INFO(BTap): Looking for TAP-Win32 with component ID tap0901, name tun2socks
INFO(BTap): Opening device .\Global{D0E7143D-B554-4146-8EB7-A98153217C3A}.tap
ERROR(BTap): DeviceIoControl(TAP_IOCTL_GET_MTU) failed
ERROR(tun2socks): BTap_Init failed
NOTICE(tun2socks): exiting

Then I downloaded and installed tap-windows-9.9.2_3.exe from OpenVPN, and it
solved the problem. However, it also seem to have downgraded my TAP drivers
from 2014-04-09 to 2012-07-02.

Anyway, case solved...

Regards,

Oskar

from badvpn.

Microsoft Windows [version 6.1.7601] 64bit

• fails with tap-windows-9.21.1.exe (NDIS 6)
• works with tap-windows-9.9.2_3.exe (NDIS 5)

Files from https://openvpn.net/index.php/download/community-downloads.html

from badvpn.

I know I'm about 4 years late to this party, but this compatibility issue has now been fixed in tap-windows6 master (OpenVPN/tap-windows6#71), and the fix should be present in the next release.

from badvpn.

Hi.

It is true that you cannot set the MTU, but this code is getting it. This is the first time I'm seeing this error, and I've tested this on different WinXP and Win7 machines.

I suspect this is a problem on your end. Perhaps a permission issue, but seems unlikely considering that opening the device succeeds.

Or maybe the most recent version of the tap-windows driver broke it? You can try older OpenVPN builds.

from badvpn.

On Tuesday, September 30, 2014 at 09:17, Ambroz Bizjak wrote:

Hi!

It is true that you cannot set the MTU, but this code is getting it. This
is the first time I'm seeing this error, and I've tested this on different
WinXP and Win7 machines.

I suspect this is a problem on your end. Perhaps a permission issue, but
seems unlikely considering that opening the device succeeds.

Or maybe the most recent version of the tap-windows driver broke it? You
can try older OpenVPN builds.

Yes, you're right, it must be an issue on my computer - I tried badvpn on
another one and was not able to reproduce the issue.

On the computer with the problem I have two TAP NICs, but that should not
make a difference, should it? Both computers are Windows 8.1 by the way.

Regards,

Oskar

from badvpn.

Seems like it bugs with the NDIS 6 driver, but is fine with the NDIS 5 one. NDIS 5 one works well though on Win7 and later, but badvpn-tun2socks gets this exact error on NDIS 6 driver from OpenVPN.

from badvpn.

NDIS 6 fails if you don't pass input parameters (even when none are needed) to the DeviceIoControl method.

So the output parameters here need to be the same as the input parameters or NDIS6 throws an error.

I would submit these changes if I could, but I can't

from badvpn.

Maybe the process is already running

from badvpn.

Hi @bemasc , I am having the same issue here with OpenVPN 2.4.7 [2019.02.21].

This is not fixed yet?

Thank you.

Well, probably because I am using a old BadVPN release, will try to compile the new version by my own. But, if anyone have it for Windows I will be glad.

from badvpn.

@tobiastromm its not so difficult, just follow: https://github.com/ambrop72/badvpn/blob/master/BUILD-WINDOWS-VisualStudio.md and get working version ;)

from badvpn.

Yep, I already do that some years ago for BadVPN server 1.999.129.

from badvpn.

Good. The current compiles fine in build setting also if select release and x64 for performance

from badvpn.

Do I need to change something from https://github.com/ambrop72/badvpn/blob/master/BUILD-WINDOWS-VisualStudio.md to get the x64 ?

from badvpn.

By default the project was set to debug build and x86 I remember. But you can click in visual studio in menu project=> build target. There you can select target architecture x64 x86 change by switching with one click. Did working for me just good. I suggest you first try by default settings first if it fixes your issue than and only than and change it later.

from badvpn.