HTTP proxy connection error

0 votes
asked Mar 23, 2011 by Chau Nguyen (120 points)
edited Mar 24, 2011

I am running the WinFormClient sample and try to connect to a ftp site using HTTP proxy. This is the error I got: Rebex.Net.FtpException: Error 403 returned by a HTTP proxy (Forbidden). ---> Rebex.Net.ProxySocketException: Error 403 returned by a HTTP proxy (Forbidden). at wWGvS.clmBMP.BFSHLEZ(String )

It works fine using IE to browse the same ftp site so I know it is not the Proxy setting.

Any idea or help will greatly appreciate.

1 Answer

0 votes
answered Mar 24, 2011 by Lukas Pokorny (90,910 points)
edited Mar 24, 2011

Please make sure your HTTP proxy supports HTTP CONNECT method. If it doesn't, it won't work with Rebex FTP.

There are two ways of making FTP servers accessible through HTTP proxy:

  • The first one is a special HTTP CONNECT method, which makes it possible to connect to virtually any port on any server on the Internet and therefore it can also be used to connect to FTP servers. After a connection is made, it is possible to communicate with the FTP server using the FTP protocol - the proxy only initializes the connection and does not affect the traffic. Rebex FTP supports this kind of proxies - this is the HttpConnect type proxy.
  • The second one is an extension of a regular HTTP GET requests that makes it possible to access FTP URIs using a web browser. Communication between the proxy and the FTP server is using the FTP protocol, but the communication between the proxy and a client on a computer on the local network is actually HTTP, not FTP. This is a huge limitation - only the very basic FTP functionality can be utilized this way and it is only intended to be used from a web browser.

If you absolutely need to use HTTP GET, then Rebex FTP can't help you, unfortunately. A decent HTTP component would be a better choice. Sorry!

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