You may receive the "Internet synchronizer exited unexpectedly on the server" error message when you try to initiate Internet synchronization of a Microsoft Access-replicated database

After you initiate Internet synchronization to exchange the data in a Microsoft Access-replicated database over an Internet connection, you may notice that the Internet synchronization is not completed successfully. Additionally, you may receive the following error message:Note Capitalization and wording for this error message has been verified to match the error message that appears on the UI.

This problem occurs when all the following conditions are true:

• The Internet server, also known as the Web server, that is running the Internet synchronizer is on a private local area network (LAN) that is connected to the Internet.
  
  Note The Internet synchronizer is named Mstrai40.exe.
• The LAN uses a router that has Network Address Translation (NAT) that is enabled to communicate with the computers on the Internet.

The Internet synchronizer tries to communicate with the Web server by using the unique external Internet Protocol (IP) address or the domain name of the Web server. Because the Web server is in the same local area network and is configured to use the same NAT router, the NAT router cannot map the external IP address or the domain name of the Web server to the internal IP address of the Web server. Therefore, the Internet synchronizer cannot connect to the Web server to do Internet synchronization successfully.

If Internet replication is setup by using the domain name of the Web server, you can resolve this problem by editing the Hosts file on the Web server. You want to map the domain name of the Web server to the internal IP address of the Web server. To do this, follow these steps.

Note You cannot use this method if Internet replication is setup by using the external IP address of the Web server.

1. Start Microsoft Windows Explorer.
2. Locate the Hosts file.
   
   By default, the Hosts file is at the following location:
   
   <WinDir>\system32\drivers\etc
   
   Note The <WinDir> placeholder is a placeholder for the path of your Microsoft Windows folder where the operating system files run from.
3. Open the Hosts file by using Notepad.
4. Add the following line at the end of the Hosts file to map the domain name of the Web server to the internal IP address of the Web server.
   
   <IP Address> <tab character> <Domain name>
   
   Note The <IP Address> placeholder is a placeholder for the internal IP address of the Web server. The <Domain name> placeholder is a placeholder for the domain name of the Web server.
   
   For example, if the domain name of your Web server is "ReplicationDomain.com," and the internal IP address of the Web server is "192.168.150.144," you must append the following line to the Hosts file on the Web server:
   
   192.168.150.144 ReplicationDomain.com
5. Save the Hosts file.
   
   Notice that you can successfully synchronize the data over the Internet.

To work around this problem, use one of the following methods:

• Use a virtual private network (VPN) so that the remote computers that participate in your Access replication can connect to your Web server for Internet synchronization.
  
  For additional information about VPN, visit the following Microsoft Web site:
  
  Virtual private networks for Windows Server 2003
  http://technet.microsoft.com/en-us/network/bb545442.aspx
• Connect the Web server to the Internet directly by removing the NAT router.
  
  When the users of your Access database replication try to connect to the Web server over the Internet connection, the external IP address or the domain name of the Web Server is correctly translated to the internal IP address of the Web server by the NAT router.

For additional information, visit the following Microsoft Web sites:

Virtual private networking: frequently asked questionsInternet synchronization with the Microsoft Jet Database Engine: a technical overview For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base: