连接状态检测原理

复制从:https://superuser.com/questions/277923/how-does-windows-know-whether-it-has-internet-access-or-if-a-wi-fi-connection-re

Here are the details of the connection status determination process:

The following list describes how NCSI might communicate with a Web site to determine whether a network has Internet connectivity:

1. A request for DNS name resolution of dns.msftncsi.com

2. A HTTP request for http://www.msftncsi.com/ncsi.txt returning 200 OK and the text Microsoft NCSI

This can be disabled with a registry setting. If you set

 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services     NlaSvc\Parameters\Internet\EnableActiveProbing

to 0, Windows will no longer probe for internet connectivity.

Apple does something very similar in iOS to detect internet connectivity and possible hotel "login" wifi pages, etc.

解决办法:

计算机\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NlaSvc\Parameters\Internet\EnableActiveProbing 改为0  禁用检测

windows 可以上网,显示无网络连接