I've been dealing with a VPN issue on Windows 11 that's really puzzling. We have a long-standing L2TP VPN setup that we've used for years with no problems. It works perfectly on most Windows 10 systems and about 95% of our Windows 11 machines. However, I've noticed that some of the recent updates seem to have caused a problem where clients can connect to the VPN but can't resolve DNS addresses to our internal servers.
Here's the situation: when I run 'nslookup INTERNALSERVER.domain', it resolves correctly every time, showing that our internal DNS is reachable. But when I try to ping that same internal server, it fails with 'ping could not find host...'. This shouldn't be happening, especially since the VPN metric is set to 1, which is the lowest possible, and routes to the internal DNS servers are also set with a metric of 1.
The crux of the issue seems to be that while nslookup works fine, other applications like ping and browsers default to using the public DNS, which has a higher metric. I suspect that a recent update has messed with DNS priority settings. Has anyone encountered a similar issue or have any ideas on how to fix this?
3 Answers
Is it possible that users who are having these issues are on AT&T? I've heard that sometimes their DNS settings can create complications with VPNs.
Have you checked if there's any DNS filtering enabled, like Akamai? Sometimes that can cause issues with DNS resolution, even if it seems like everything's configured correctly.
Nope, we aren't using any DNS filtering at all.
Can you try pinging that server by its IP address? If that works, it could further pinpoint the DNS issue you're experiencing.
Yes, I can ping the server directly by its IP without any problems.
No, none of our users are with AT&T; they're all in Canada.