How to enable passive CERN FTP connections through ISA Server 2000 or ISA Server 2004

This article describes how to enable programs to make a passive CERN FTP connection through Microsoft Internet Security and Acceleration (ISA) Server 2000 or through ISA Server 2004 Standard Edition and ISA Server 2004 Enterprise Edition.

Enable passive FTP connections

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

Programs that must establish a passive CERN FTP connection over an ISA server establish a port-mode connection instead of a PASV-mode connection. You can edit the registry on the ISA server to allow FTP requests that are made by using the Web proxy component to use PASV mode. To do this, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and double-click the following registry subkey:
   HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/W3Proxy/Parameters
   Note When you use ISA Server 2004 SP2, you must first create the Parameters key under the W3Proxy key.
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type NonPassiveFTPTransfer as the new value, and then press ENTER
5. Right-click NonPassiveFTPTransfer, and then click Modify.
6. In the Value data box, type 0 (zero), and then click OK.
   
   Note To return this setting to the default value, set the NonPassiveFTPTransfer value to 1.
7. Exit Registry Editor, and then use one of the following methods as appropriate:
   • If you are running ISA Server 2000, restart the ISA Server Web Proxy service. To do this, follow these steps:
     1. Click Start, click Run, type cmd, and then click OK.
     2. At the command prompt, type net stop w3proxy, and then press ENTER. You receive the following output:

        The Microsoft Web Proxy service is stopping.
        The Microsoft Web Proxy service was stopped successfully.
        
        						

     3. Type net start w3proxy, and then press ENTER. You receive the following output:

        The Microsoft Web Proxy service is starting.The Microsoft Web Proxy service was started successfully.
        
        						

     4. Type exit, and then press ENTER to exit the command prompt.
   • If you are running ISA Server 2004, Standard Edition, restart the Microsoft Firewall service. To do this, follow these steps:
     1. Click Start, click Run, type cmd, and then click OK.
     2. At the command prompt, type net stop fwsrv, and then press ENTER. You receive the following output:

        The Microsoft Firewall service is stopping.
        The Microsoft Firewall service was stopped successfully.
        
        						

     3. Type net start fwsrv, and then press ENTER. You receive the following output:

        The Microsoft Firewall service is starting.The Microsoft Firewall service was started successfully.
        
        						

     4. Type exit, and then press ENTER to exit the command prompt.

For more information about a problem that you might experience after you enable passive mode FTP through ISA Server 2004, click the following article number to view the article in the Microsoft Knowledge Base: For more information, click the following article number to view the article in the Microsoft Knowledge Base: For additional help and support with ISA Server, visit the following Web sites: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.