DNS requests leak

[davidparks21]

I've set up a new (dev) OpenVPN on a linux server. I've configured it to push googles 8.8.8.8 DNS server to the clients.

I'm on a windows box. nslookup shows that it's using the 8.8.8.8 DNS server just fine.

When I do a packet capture I see that all traffic, including DNS is going through the VPN (I go to a random website to ensure DNS is called, also nslookup's don't show any traffic outside of the VPN).

There is a case, however, where DNS requests are going through my local DNS server, I think it's when a flash app comes up.

I'm racking my brain trying to figure out how or why there are any exceptions. Does anyone have a thought on what I might do to track down exactly what's happening here? How can I understand the routing logic going on behind the scenes for the odd case here?

Thoughts? Thank you!
David

[krzee]

Check if your local server is still in your resolv.conf
you may need to tweak the update-resolv-conf script to remove it, since it sounds like an app is not behaving as expected

<edit>
oops the client is windows...
Check if windows still knows about the local dns server, same thing different OS

[davidparks21]

When I do an ipconfig /all command I see both adapters have a DNS server listed. Beyond this command I'm not familiar with how I might configure OpenVPN to disable all other DNS servers when it is enabled.

Thanks for the reply,
David

[krzee]

in unix i would know... for windows all i can think is that you could set your machine to always just use 8.8.8.8... unless you have a reason that is not ok

[davidparks21]

Ok, I'll continue to dig to see if I can do this automatically in windows. Is there some script that OpenVPN runs on connect that I can customize for this purpose?

Incidentally, I just started my test on windows, but I'll need to do the same on Linux/OSX, can you point in a direction on that?

Thanks!
Dave

[krzee]

in windows, it is done from within openvpn
in linux/unix you need the update-resolv-conf script, which can be edited if necessary