How to Specific Port Range for IIS FTP in passive mode ?

Configuration

1. Open Internet Information Services (IIS) Manager.
2. Double-click FTP Firewall Support.
3. Enter the range of port number in the Data Channel Port Range field.
4. Click Apply.
5. Run dialog : services.msc.
6. Find the Microsoft FTP Service.
7. Right-click the service and click restart.

Note : It is not recommended using single port because it will limit the number of Client IP – Client Port – Server Port combinations. The FTP sessions are uniquely identified thanks to this combination. Using a single server port will result in having the same combination which may result in the concurrent FTP requests to be rejected. If the Data Channel Port Range field is grayed out, make sure that you are changing the server-level settings.

Confirmation

1. Connect to your FTP host via an FTP client to confirm that the FTP service uses only the assigned port. Then check the IIS logs in this folder : C:\inetpub\logs\LogFiles\FTPSVC2.

Note : For the unsecured FTP service, IIS doesn’t use the port you assigned. Instead, it uses a random port number in the range from 1025 through 65535. IIS uses the port you specified in Data Channel Port Range field only via secure FTP service.