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Q239041: IIS: The FTP PORT Command May be Issued Before Client has Logon

Article: Q239041
Product(s): Internet Information Server
Version(s): winnt:5.0
Operating System(s): 
Keyword(s): kbDSupport kbiis500
Last Modified: 04-FEB-2000

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The information in this article applies to:

- Microsoft Internet Information Services version 5.0 
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SYMPTOMS
========

When using the FTP Server that ships with Internet Information Services 5.0, you
may notice some supposedly inconsistent behavior. For example, if you were to
create a control connection to a restricted FTP server (one in which the you do
not have a valid logon), then issue a PORT command, this command would result in
the server returning the following message:

  200 PORT Command Successful.

You are never prompted for credentials during this phase of the FTP connection
process even though the FTP site has been restricted (meaning anonymous access
is disabled). This may be looked at as a possible security problem, but it is
actually normal behavior for FTP.

CAUSE
=====

FTP requires that you are identified before a connection is officially
established. In other words, a connection has not officially been made yet. You
cannot transfer files unless you first logon the server.

STATUS
======

This is a known issue with Internet Information Services 5.0 (and most FTP
servers as well).

Additional query words: iis ftp port

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Keywords          : kbDSupport kbiis500 
Technology        : kbiisSearch kbiis500
Version           : winnt:5.0
Issue type        : kbbug
Solution Type     : kbpending

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