VPN stopped working last week

Question

Hi guys, all of a sudden last week any of my MS VPN connection to the server will not connect at all. I checked with the other admin and he can connect and our users are connecting ok. its affected my Desktop and notebook.

I have tried resetting the network adapters, removing VPN and setting them back up.

Uninstalled all network devices.

Updated the BIOS, network adapters.

Even found a post saying the KB5003637 and KB5003254 updates caused his issue, uninstalling made no difference.

The error is.

CoId={D41381AD-2F3A-469B-867E-3E7F980D06C2}:The initial Secure Socket Tunneling Protocol request could not be successfully sent to the server. This can be due to network connectivity issues or certificate (trust) issues. The detailed error message is provided below. Correct the problem and try again.

A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider.

Answer 1

Hi guys, I had run sfc /scannow and a dism commands.

I solved the issues last night, it turned out to be my ASUS router, the AiProtection Two way IPS was blocking it. Suspected DOS attack. I have scanned both systems for any sort of infections and found nothing.

I expect it was a false positive.

Answer 2

Try open Command prompt as administrator and type the following command:

sfc /scannow

You may check the event viewer and check errors and warning during the time problem started and from there investigate the issue.

Answer 3

Hi ,

Before we go further, I would like to confirm the following questions:

1. What's the OS version of your VPN client? windows 10 2004 or 20H2?
2. If you change VPN type to automatic or PPTP, can you connect to VPN successfully? If not, what's the exact error message?
3. In order to narrow down whether the problem is related with firewall, please temporarily disable windows firewall to do a check.
4. Check the network connection between VPN client and VPN server, check whether you can ping VPN server's IP address successfully.

Best Regards,
Candy

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