DOCUMENT:Q242528 06-AUG-2002 [winnt] TITLE :Time-Out to Unreachable Computers Is Excessive PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0, Terminal Server Edition ------------------------------------------------------------------------------- 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: Q256986 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 \\\ipc$, which allocates a server list entry and attempts to connect. The returned status is "0xC00000BE invalid connection," and the last connect time is set in the server entry. Then, the application context attempts a connection to \\\, which allocates a second server list entry and attempts to connect. During this time, the cleanup thread wakes up and determines that the first server list entry has expired and dereferences and frees it. The second connection attempt then returns "failure 0xC00000BE." The driver then reiterates on \\\ipc$ 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 \\\ 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 ========== A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows NT 4.0, Terminal Server Edition, service pack that contains this fix. To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: Date Time Size File name Platform -------------------------------------------------------------- 10/28/1999 11:03 PM 266,576 Rdr.sys Intel 10/28/1999 11:09 PM 510,032 Rdr.sys Alpha 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. STATUS ====== Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. 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. Additional query words: ====================================================================== Keywords : Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbNTTermServ400 kbNTTermServSearch Version : winnt:4.0 Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.