What Is an FTP Server?

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An FTP server is simply software that can respond to FTP requests, just as a Web server is a computer that has an application listening to and responding to HTTP requests on port 80. With FTP servers, the software must listen for FTP requests on port 21. Microsoft’s Internet Information Server package includes an FTP server. It basically allows users to upload files to your computer. Bear in mind that this can be the source of significant security risks. If you allow users to upload any file they like to your Web site, then someone could upload harmful software to your system. It is best to go to the Web site for the FTP server you prefer and read all of the documentation they have before trying to run an FTP server. This chapter is meant to give you an introduction to the topic and show you how to set up the basic configuration options.

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