FTP and Firewalls

Many corporate sites and other computers with firewalls are configured such that an FTP (File Transfer Protocol) download cannot work properly.

FTP is generally considered faster and more reliable than an HTTP download (a download controlled completely by the browser and web site using the same "port" as a web page). However, the normal way that FTP works is that once you activate an FTP download, the FTP server contacts your computer and attempts to assign a random port on your computer (any port from 1023 to 65,000) to use for the actual data download. Most firewalls will see this as an intrusion attempt and disallow the connection and thus the download will fail.

Some browsers let you select PASV or Passive Mode for FTP downloads. In Internet Explorer, this option is found under Internet Options, Advanced. When this mode is selected, FTP servers will not attempt to assign a port on your computer, but will instead use only the two "standard" FTP ports, ports 20 and 21. Even with Passive mode, some firewalls will still refuse to allow an FTP connection.

If FTP cannot be used on your computer, you should use the HTTP download option.

We continue to offer FTP for those customers that can use it since it works very well for downloading large files and supports "download resuming" in cases where a download got interrupted.