Heiko Hund wrote:
Hi,
On Tuesday 06 April 2010 22:36:31 Johan Ymerson wrote:
> I have tested on 3 PC's with Windows XP, all 3 show the same
problem, at
> almost 100% of my connection attempts. OpenVPN 2.0.9 does not have this
> issue (ie. reverting back to 2.0.9 on the same machines with the same
> config never show the problem).
We also tried 2.0.9 but were able to reproduce the bug with it as
well, so it
has nothing to do with the openvpn driver version involved. I came to the
conclusion that it's rather some kind of race condition in the Windows
XP DNS
resolver. At least I haven't seen this problem on Vista or 7 personally.
> Is this problem known, and is someone working on it?
> I can of course help debugging this, but I don't have the development
> environment needed to compile the Windows binaries.
Not much to debug anyway. The DNS servers get passed correctly via
DHCP and
Windows actually takes notice of them as they show up in `ipconfig /all`.
Problem is that XP resolver somehow forgets to reprioritize the DNS
servers
list after an DHCP update sometimes and sticks with the old preferred
name
server until the scheduled reprioritization. At least that's my personal
conclusion. And it would explain why a /renew fixes it.
We've contacted Microsoft tech support about this issue. If anything
like a
fix comes out of that I'll post an update here. If not we'll have to
consider
a workaround of some kind, but let's wait with that discussion until
we're
sure it's not fixable the right way.
isn't
ipconfig /flushdns
or
net stop dnscache
net start dnscache
enough? This might be related to
http://support.microsoft.com/kb/311218
I've recommended to people on the -users list to use an 'up' script with
net stop dnscache
net start dnscache
this has worked in 99% of the cases.
cheers,
JJK
