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Added by Rick Trader May 11, 2016

Have you seen the following in your system tray / notification area before and wondered why it is there?

There could be multiple reasons why you are seeing the above network icon, but first let me explain what service / process / feature is causing the icon to be displayed with an exclamation mark. In Windows 7 and Windows Server 2008 R2 Microsoft introduces a new feature called Network Connectivity Status Indicator (NCSI). This feature is part of Network Awareness. One of the first misconceptions of the icon is that you have lost Internet connectivity. Which is not necessarily the case. Let me explain.

When Network Awareness detects a change in your network configuration it will attempt to connect to a specific URL at Microsoft. I will explain this a little later in this BLOG. So what could trigger the NCSI to communicate with Microsoft.

• A computer is turned on.
• A computer is restarted.
• A network connection is cycled between disabled and enabled.
• A computer is connected to a wireless network.

NCSI uses one of the following processes to determine if you have Internet connectivity.

• A HTTP get request is sent to:
  • HTTP://www.msftncsi.com/ncsi.txt.
  • The text file consists of Microsoft NCSI.
• Attempt to conduct a name resolution request is sent to DNS:
  • dns.msftncsi.com
  • DNS must resolve to 107.255.255.

Even though you may have Internet connectivity, NCSI may still give you an indication that you do not. Here are some of the scenarios where it can give you the wrong indication.

1^st scenario:

• Your computer can connect to a resource on the Internet by using its IP address but you cannot resolve the URL.
  • Your DNS may be misconfigured or not configured within your TCP/IP settings.
  • As a result, NCSI will not be able to resolve msftncsi.com or dns.msftncsi.com.

2^nd scenario

• Your computer can connect to a resource on the Internet by using its IP address but you cannot resolve the URL.
  • Your DNS may be offline or has lost connectivity with the Internet.
  • You have lost connectivity to your DNS.
  • As a result, NCSI will not be able to resolve msftncsi.com or dns.msftncsi.com.

So the best way to determine if the icon is displaying whether or not you have lost connectivity to the Internet or you have lost name resolution is to attempt to connect to an Internet based resource by its IP address. If you can connect to the resource then you know you have connectivity to the Internet. At this point it most likely will become a name resolution troubleshooting issue. Check with your DNS administrators to ensure there are no issues there.

For more information see my other posts:

How to Disable Network Connectivity Status Indicator (NCSI) with Group Policy

Configuring Network Connectivity Status Indicator (NCSI) with Group Policy

Configuring Internet Restrictions with Internet Communications Management with Group Policy

Until next time – Ride Safe!

Rick Trader
Windows Server Instructor – Interface Technical Training
Phoenix, AZ