Time-Out to Unreachable Computers Is Excessive (242528)

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

When you are attempting to connect to a computer that is unreachable in a Terminal Server session, you may experience an excessive delay before the attempted connection times out. The typical, expected delay of less than a minute does not occur. Instead, Terminal Server may take from 90 seconds to 20 minutes before an "Unsuccessful" error message is returned. This may cause the program that requested the network connection to stop responding (hang).

CAUSE

There are several iterations of calls to the redirector to establish a connection. First, the system context attempts a connection to \\server\ipc$, which allocates a server list entry and attempts to connect. The returned status is "0xC00000BE invalid connection," and the last connect time is set in the server entry. Then, the application context attempts a connection to \\server\share, which allocates a second server list entry and attempts to connect. During this time, the cleanup thread wakes up and determines that the first server list entry has expired and dereferences and frees it. The second connection attempt then returns "failure 0xC00000BE." The driver then reiterates on \\server\ipc$ by using the Multiple UNC Provider (MUP) and does not find the server list entry. A new one is allocated and a connection attempt is made. During this time, the cleanup thread wakes up again and determines that \\server\share has expired and dereferences and frees it. This continues until the timing is just right and both server list entries can be found. Note that these connection attempts can take a minute or so each because the server does not exist and Windows is relying on a time-out to determine this.

RESOLUTION

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Windows NT 4.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

152734 How to obtain the latest Windows NT 4.0 service pack

WORKAROUND

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
One way to work around the problem is to configure the following registry setting:

HKLM\System\CurrentControlSet\Services\RDR\Parameters

Value Name: FailedConnectTimeout
Data Type: REG_DWORD
Data: 0x80 (This is about 120 seconds)

This registry setting does not really solve the problem, but avoids it. The second attempt to connect should really be locating the server list entry rather than reattempting the connection. The redirector code has been changed to prevent the need for the futile second connection attempt.

MORE INFORMATION

The length of the hang changes depending on the WINS configuration and the name resolution used by the destination server and Terminal Server. If the destination server's IP address cannot be resolved, the hang occurs for less than 2 minutes.

If the destination server's IP address resolves successfully, Terminal Server then attempts a connection. Address Resolution Protocol (ARP) takes about 50 seconds for each unsuccessful attempted connection, causing the program to hang for more than 20 minutes.