Large number of connections established on front-end servers that are running Exchange 2000 Server

You may notice one or more of the following behaviors on your Microsoft Exchange 2000 Server front-end servers:

• The server starts rapidly establishing Transmission Control Protocol (TCP) connections to itself, which are kept open indefinitely. After you stop all client connections to the front-end server, the connections remain open.
• The Inetinfo.exe process consumes most of the available memory on the computer and accounts for a very large number of handles and threads. However, the Inetinfo.exe process may or may not consume an inordinate number of CPU cycles.
• The log files for the virtual server (Web site) that provides the services for Exchange 2000 Server list a large number of entries from a single user attempting to access the public Virtual directory. These entries are similar to the following.
  
  Note These messages do not necessarily indicate malicious activity.

  2002-02-06 11:02:09 192.168.1.100 test 192.168.1.120 80 GET
  /public/folder1/ Cmd=contents 503
  Exchange-Server-Frontend-Proxy/6.0+Mozi...

  -and-

  2002-02-06 11:02:09 192.168.1.100 test 192.168.1.120 80 PROPFIND
  /public/folder1/ - 503 Exchange-Server-Frontend-Proxy/6.0+Mozi...

  Note The preceding error messages have been wrapped for readability.

When this issue occurs, the following event may appear in the system event log:

Event ID: 2019
Source: Srv
Description: The server was unable to allocate from the system nonpaged pool because the pool was empty.

This behavior may occur if the front-end server contains a mounted public folder store. This may occur for one or both of the following reasons:

• The public folder store may have been previously mounted and used by some users.
• The front-end server may have been the first Exchange 2000 Server in the organization, and therefore it contains the system default public folders.

Microsoft recommends that you not run mailbox or public folder databases on front-end servers. This is because mailbox or public folder databases are not necessary on front-end servers, because front-end servers do not host mailboxes.

To resolve this issue, follow these steps.

Stop and disable the mailbox and public folder databases

1. Start Exchange System Manager.
2. Expand Servers, expand your server, and then expand First Storage Group.
3. Right-click Mailbox Store (ServerName), click Dismount Store, and then click Yes to dismount the store.
   
   Note If you use the front-end server as an SMTP-bridgehead server, you must have a mailbox store mounted on the server. In this case, do not dismount and delete this store, but make sure you do not have any mailboxes stored on this server.
4. Right-click Mailbox Store (ServerName), and then click Properties.
5. Click the Database tab, click to select the Do not mount this store at startup check box, and then click OK.
6. Right-click Public Folder Store (ServerName), and then click Dismount Store.
   
   Warning Before you dismount and delete the Public Folder Store, make sure that the public folders have a replica on another public folder store. Otherwise, you may lose information.
7. Click Yes to dismount the Public Folder Store.
8. Right-click Public Folder Store (ServerName), click Delete, click Yes, click OK, click EXBE, click OK, and then click Yes to delete the public folder store. Click OK to close the message.
9. Quit Exchange System Manager.

Disable the Microsoft Exchange Information Store

After you dismount the mailbox and public folder databases, you can disable the Information Store service because it no longer performs any functions on the front-end servers. By removing unnecessary services, you reduce loading and improve security.

To disable the Microsoft Exchange Information Store:

1. Start the Services snap-in. To do this, click Start, click Run, type services.msc in the Open box, and then click OK.
2. Right-click Microsoft Exchange Information Store in the Name list, and then click Properties.
3. In the Startup type list, click Disabled, click Stop, click Yes to confirm the stopping of the POP3 and IMAP4 services, and then click OK.
4. Right-click Microsoft Exchange POP3, and then click Properties.
5. In the Startup type list, click Manual, and then click OK.
6. Right-click Microsoft Exchange IMAP4, and then click Properties.
7. In the Startup type list, click Manual, and then click OK.
8. Quit the Services snap-in.

For additional information, click the following article number to view the article in the Microsoft Knowledge Base: For additional information about Exchange 2000 front-end and back-end topology, please visit the following Microsoft Web site: