How does Win 7 know that the network is limited

        Recently, the author was asked to communicate with netizens such a question, how does win7 know that your network is limited? Your computer is equipped with a Win7 system. Maybe you will notice that sometimes the system will issue a "limited network connection" warning. This limitation is mainly designed for international websites, as long as you visit an international website. limit.

So the question has been very clear, that is, Microsoft is how to know your network connection status of it? The author below briefly explains the reasons for everyone, in fact, it is very simple.

When each user connects to the network, the system will automatically send a domain name access request to Microsoft. The result of the access is the Network Connectivity Status Indicator (NCSI). In fact, Vista was the first to adopt this feature.


NCSI first perform a DNS lookup on dns.msftncsi.com, then request access to the file http://www.msftncsi.com/ncsi.txt, which is a plain text file contains only the text " Microsoft NCSI". Dns.msftncsi.com should resolve to 131.107.255.255, if the address does not match, then it will guess that the network connection is not working properly.



Edit Comment: For this feature of NCSI, some users may be concerned about privacy issues, because Microsoft will record the IP address of each connection in the website log. If you don't want Microsoft to know your network connection, you can modify the registry to disable the NCSI service, or modify it to access your own server.