Your ASP or ASP.NET application may restart or you may lose the session object when more SMB requests exist than the Web server can process (843584)

RESOLUTION

To work around this problem, increase the number of connections that you can have by resetting the registry values of the MaxCmds and the MaxMpxCt keys. The recommended values are 253, 1124, and 2048. To do this, follow these steps.

Note In this section, the LanmanWorkstation is the Web server and the LanmanServer is the remote share.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

1. Verify that the setting for the MaxCmds registry value on the Web server is 50 or larger. To do this, follow these steps:
   
   Note The MaxCmds and MaxMpxCt entries are REG_DWORD decimal entries. If they do not exist, you may create them as new REG_DWORD values. The range of values for these registry entries is between 0 and 65535. If the MaxCmds and MaxMpxCt keys do not exist, create the keys.
   1. Click Start, click Run, type regedit, and then click OK.
   2. Locate and then click the following key in the registry:

      HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\parameters

   3. In the right pane, double-click the MaxCmds value.
   4. In the Value box, verify that the number is 50 or larger. If the number is not larger than 50, increase the value to one of the recommended values.
   5. Quit Registry Editor.
   Note In a Microsoft Windows Terminal Services environment, you may have to set the MaxCmds registry value to 500 or larger. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

   232476 Terminal Server client connections and logon limited by MaxWorkItem and MaxMpxCt values

2. Verify that the setting for the MaxMpxCt registry value on the Microsoft Windows 2000-based server computer is 50 or larger. If the MaxCmds and MaxMpxCt keys do not exist, create the keys. To do this, follow these steps:
   1. Click Start, click Run, type regedit, and then click OK.
   2. Locate and then click the following key in the registry:

      HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\parameters

   3. In the right pane, double-click the MaxMpxCt value.
   4. In the Value box, verify that the number is 50 or larger. If the number is not larger than 50, increase the value to one of the recommended values.
      
      Note The MaxMpxCt value determines the maximum number of active requests that the server allows for at the same time from an individual client.
   5. Quit Registry Editor.
   Note On SMB servers that are not based on Windows 2000, the MaxMpxCount registry value has the same function as the MaxMpxCt registry value on non-Windows 2000-based Windows operating systems.
3. Repeat steps 1 and 2 on the remote share.

Note If you increase these values on the x86 platform, the file server and the IIS clients will consume additional non-paged pool memory. Non-paged pool memory has an upper limit of 256 megabytes (MB). Lots of clients together with lots of connections can consume all the non-paged pool memory on the file server. Use Performance Monitor to watch this counter and to make sure that it is not approaching the limit. On the x64 platform, non-paged pool memory has an upper limit of 128 gigabytes (GB). Therefore, you can increase these values to the maximum value. For more information about the differences between non-paged pool memory on the x86 platform and on the x64 platform, click the following article number to view the article in the Microsoft Knowledge Base: