Windows TAP Driver 9.21.0 and DHCP in Bridge Mode

[deleted]

Hi

i have a working setup of OpenVPN with it running on linux in bridge mode. i can connect successfully with linux clients to it (and receive an IP address via the DHCP server on the linux box) and also with Windows clients that are running a TAP Version of 9.9.2 or lower (http://build.openvpn.net/downloads/releases/).

If a windows client uses the 9.21.0 version of the TAP driver (the one that is bundled with the OpenVPN 2.3.4 windows package), the VPN connection gets created, i see the DHCPREQUEST coming in on the linux box, the and DHCP server sends out an DHCPOFFER. This DHCPOFFER doesn't seem to be received by the windows networking system, as the client retries the DHCPREQUEST over and over. Downgrading ONLY the TAP driver to version 9.9.2 makes it work (still with openvpn 2.3.4).

Is this a bug? or has something changed how the TAP driver works or needs bo be configured? has someone else a simliar setup and seen that problem?

greets
KoS

[deleted]

sure...sorry... thought the version stating in the post were fine.

server side: debian wheezy (up-to-date) -> OpenVPN 2.2.1 i486-linux-gnu [SSL] [LZO2] [EPOLL] [PKCS11] [eurephia] [MH] [PF_INET6] [IPv6 payload 20110424-2 (2.2RC2)] built on Jun 19 2013
client site: windows 7 (32 and 64 bit, but also on win8 the same problem), latest openvpn packages from the website -> openvpn-install-2.3.4-I603-i686.exe -> OpenVPN 2.3.4 i686-w64-mingw32 [SSL (OpenSSL)] [LZO] [PKCS11] [IPv6] built on Aug 7 2014
library versions: OpenSSL 1.0.1i 6 Aug 2014, LZO 2.05
Originally developed by James Yonan Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>

but as i mentioned, the problem seems to be the TAP virtual ethernet adapter. the VPN connections gets always up as desired, but then windows doesn't receive an DHCP offer (which IS sent from the DHCP server running on the vpn server).

thanks.

[deleted]

Traffic wroteThe TAP driver is completely independent of OpenVPN ..

not really... the TAP driver is bundled in the windows installation packages.....

Traffic wrote
kosli wroteclient site: windows 7 (32 and 64 bit, but also on win8 the same problem), latest openvpn packages from the website -> openvpn-install-2.3.4-I603-i686.exe -> OpenVPN 2.3.4 i686-w64-mingw32 [SSL (OpenSSL)] [LZO] [PKCS11] [IPv6] built on Aug 7 2014
library versions: OpenSSL 1.0.1i 6 Aug 2014, LZO 2.05
The new NDIS6 TAP driver.

Best to roll back to a stable version.

which is the stable and which is the unstable version? on the http://openvpn.net/index.php/open-source/downloads.html download site it looks for me as OpenVPN 2.3.4 is the current stable and OpenVPN 2.3.2 is an old-stable version. there is neither mentioned which TAP Driver versions are included, and if it is a stable or unstable version. the only thing that i see is that the TAP driver listed on the download site is 9.9.2_3. the one bundled with OpenVPN 2.3.4 is 9.21.0 -> but this is only visible AFTER installing the bundle. could someone please make that somehow "visible" on the download page?

regarding the DHCP problem with the "unstable" 9.21.0 TAP driver, should i fill a bug report for that? or i can i somehow help out to diagnose the problem?

thanks
KoS

[deleted]

ah, now i saw at least the text "The I603 installers are bundled with a modern, NDIS 6-compatible tap-windows driver which only works on Windows Vista and above."
from the table with the downloads it is unclear what means "Windows XP and later" and "Windows Vista and later", without mentioning that there is a different TAP driver included.

a sample table how it could look like: http://ip.kos.li/downloads.html

[deleted]

debbie10t wroteDid you want to volunteer some help ?

if i can help in some kind, sure, so i can return something to the openvpn community! just depends on "what" :-)