[Openvpn-devel] Failure to configure TAP device under Windows

[David W. <dw...@in...>]

I installed OpenVPN on Windows 7 64-bit using
openvpn-install-2.3.2-I003-x86_64.exe and ported the OpenConnect VPN
client¹ to use the TAP device.

It created a TAP device as part of the installation, named 'Local Area
Connection 3'. Attempting to configure IP addresses on this device fails
thus:

C:\> netsh interface ip set address "Local Area Connection 3" static 10.0.0.1 255.0.0.0
Element not found.

I was able to configure the IP addresses using the Control Panel GUI,
and managed to get things working at least for Legacy IP. If I attempt
to configure IPv6 the same way, it tells me that it needs to reboot to
assign an IPv6 address to the interface (yay, Windows!), and then when
it comes back up still has no IPv6 address. Repeating causes another
reboot and the same behaviour.

But although I can make it pass packets with manual configuration,
'netsh' never works on this device.

I can find no clue what the 'Element not found' error actually means, or
why it happens. Is it a known problem with the TAP driver, or with
Windows networking?

If I create a *new* TAP device using the 'Add a new TAP virtual
ethernet[sic] adapter' menu option (after manually running it as
Administrator because it doesn't work out of the box), I *can* use netsh
to configure the new one — at least for Legacy IP. IPv6 still fails with
'Element not found'.

On another Windows 7 machine, it all worked fine.

I am not particularly familiar with Windows — is this just the kind of
unreliable behaviour one normally expects with it, and not worth
mentioning? Or is there some bug here that we could actually deal with?

-- 
dwmw2

¹ http://www.infradead.org/openconnect/