Windows Ten L2TP 809 error

Today I do not know why, has been working normal L2TP can not connect. I'm using surface Pro 3,windows 10 Pro, the operating system keeps updating automatically, and I haven't installed any software recently. After clicking Connect, wait for a period of time to report 809 error (Starting with Windows 10, the dial-up interface no longer displays the error code, to the system log to check). The same network environment, the same L2TP, colleagues of Windows 8.1 is normal, and another colleague running Windows 10 's notebook is also unable to connect. You can therefore conclude that the problem is in Windows 10. My system has always been "bare-Ben", no numbers, penguins and other big-god security software.

After a toss-up, the final summary is as follows:

Registry, there are two changes, do not miss out. My original system is not the first (PROHIBITIPSEC).

Windows Registry Editor Version 5.00[hkey_local_machine\system\currentcontrolset\services\rasman\parameters] " ProhibitIpSec "=dword:00000000[hkey_local_machine\system\currentcontrolset\services\policyagent]" AssumeUDPEncapsulationContextOnSendRule "=dword:00000002

Check system services to set the following 3 services to "auto" start

Remote Access Auto Connection managerremote access Connection managersecure Socket tunneling Protocol Service

Finally, reboot, connect, fix!

But this question still feels strange, is the Windows 10 update trouble? Still is... To know that Windows 10 built-in search engine is already Baidu ... Don't... Uh...

Windows Ten L2TP 809 error