Select the product you need help with
- Internet Explorer
- Windows Phone
- More products
Windows Vista may disconnect client communications that use TCP port 1723
Article ID: 946567 - View products that this article applies to.
Important This article contains information that shows you how to help lower security settings or how to turn off security features on a computer. You can make these changes to work around a specific problem. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this workaround in your particular environment. If you implement this workaround, take any appropriate additional steps to help protect the computer.
Consider the following scenario:
This problem may occur when Windows Vista disconnects from a client because the client connection is determined to be invalid.
When a connection is made through TCP port 1723 in Windows Vista, Windows Firewall recognizes the connection as being established through PPTP. By default, Windows Firewall uses a stateful PPTP protocol analyzer to determine whether it can receive packets through the TCP port 1723 connection. Therefore, the stateful PPTP protocol analyzer may reject as invalid any traffic that uses a protocol other than PPTP.
Warning This workaround may make a computer or a network more vulnerable to attack by malicious users or by malicious software such as viruses. We do not recommend this workaround but are providing this information so that you can implement this workaround at your own discretion. Use this workaround at your own risk.
To disable the stateful PPTP protocol analyzer, use one of the following methods.
Method 1: Use an elevated command prompt
Method 2: Use Group Policy
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/939321/ )Error message when you use Outlook 2007 in Windows Vista to try to connect to a computer that is running Exchange Server 2003: "Task reported error 0x8004011D. The server is not available"
Article ID: 946567 - Last Review: April 7, 2008 - Revision: 3.1