百分百

Windows确认设置了下列注册表项：

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\RasMan\Parameters]
"ProhibitIpSec"=dword:00000000

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PolicyAgent]
"AssumeUDPEncapsulationContextOnSendRule"=dword:00000002

并确认启用了下列服务：

• IPsec Policy Agent 手动
  
• Remote Access Auto Connection Manager 手动
  
• Remote Access Connection Manager 应设为自动
  
• Secure Socket Tunneling Protocol Service 手动
  

$ sudo touch /etc/ppp/options
$ sudo vi /etc/ppp/options
plugin L2TP.ppp
# l2tpnoipsec  # 这一行先注释掉，不行再启用