My colleague got a windows 2012 r2 server setup the Past few days ago (inherited) and trying to connect at home with L2TP PSK.
It works immediately with MacOS as well as on his Android phone.
New windows 10 Surface Pro, as well as a Windows 10 Pro Laptop both, cannot connect and give this error:
The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.
Here’s what he tried so far:
Adding registry key to enable nat to nat VPN:
Data Value: 2
Made sure the services “IKE key generation module and AuthIP” and “IPSEC policy agent” are enabled
Added firewall rule to allow UDP 500,4500 inbound/outbound
Enabled MS-CHAP v2 in the security tab of the VPN connection
Tried connecting via the control panel vs taskbar
Restarting machine and services.
Uninstalling WAP devices in device mgr and reloading.
he is wondering if the setup on the server-side might be incorrect. at least for what a windows 10 machine might require to connect. he thinks it’s set up right since Android & macOS have no problem but maybe there’s something that only pertains to windows?
Well If anyone has some more ideas they can share us