The IIS-based FTP service supports both active and passive mode
connections, depending on the method that is specified by the client.
IIS does not support disabling either active or passive connection
Unlike HTTP and other protocols used on the Internet, the
FTP protocol uses a minimum of two connections during a session: a
half-duplex connection for control, and a full-duplex connection for
data transfer. By default, TCP port 21 is used on the server for the
control connection, but the data connection is determined by the method
that the client uses to connect to the server, as detailed below.
Active-mode FTP connections are sometimes referred to as "client-managed" because the client sends a port
command to the server, over the control connection. The command
requests the server to establish a data connection from TCP port 20 on
the server to the client, using the TCP port that is specified by the port command.
Passive-mode FTP connections are sometimes referred to as "server-managed", because after the client issues a pasv
command, the server responds with one of its transient ports used as
the server-side port of the data connection. After a data connection
command is issued by the client, the server connects to the client using
the port immediately above the client-side port of the control
In Passive-mode IIS FTP randomly choose to response
with port ranging within 1024 - 65535 by default. To further limit these
huge port range, system administrator can configure a metabase property
key named PassivePortRange, this property key only
exist in IIS 6.0, for IIS 5.0 in Windows 2000, system administrator need
to install Service Pack 4 and add in PassivePortRange key in system registry.
To change the PassivePortRange for IIS, perform the procedure that is described in one of the following sections.
For Windows 2003 Server
a) To Enable Direct Metabase Edit
1. Open the IIS Microsoft Management Console (MMC).
2. Right-click on the Local Computer node.
3. Select Properties.
4. Make sure the Enable Direct Metabase Edit checkbox is checked.
b) Configure PassivePortRange via ADSUTIL script
1. Click Start, click Run, type cmd, and then click OK.
2. Type cd Inetpub\AdminScripts and then press ENTER.
3. Type the following command from a command prompt.
adsutil.vbs set /MSFTPSVC/PassivePortRange "5500-5700"
4. Restart the FTP service.
You'll see the following output, when you configure via ADSUTIL script:
Microsoft (R) Windows Script Host Version 5.6
Copyright (C) Microsoft Corporation 1996-2001. All rights reserved.
PassivePortRange : (STRING) "5500-5700"
For Windows 2000 Server
This article contains information about modifying the registry. Before
you modify the registry, make sure to back it up and make sure that you
understand how to restore the registry if a problem occurs.
In order for this PassivePortRange to work in Windows 2000, system administrator must install Service Pack 4
(SP4) or later, For additional information, visit the following article
number to view the article in the Microsoft Knowledge Base:
260910 How to Obtain the Latest Windows 2000 Service Pack
Configure PassivePortRange via Registry Editor
1. Start Registry Editor (Regedt32.exe).
2. Locate the following registry key:
3. Add a value named "PassivePortRange" (without the quotation marks) of type REG_SZ.
4. Close Registry Editor.
5. Restart the FTP service.
Note: The range that FTP will validate is from 5001 to 65535.