> Curt Sampson wrote:
> ........
> > All that means is that you have an http proxy; netscape uses the
> > HTTP protocol to request proxies to do the FTP request (though it
> > does use the FTP protocol directly when there's no proxy server in
> > use).
>
> This is somewhat confusing. Can anyone explain it in laymen's
> terms....
Sure.
> e.g. when I go to ftp://ftp.sunsite.unc.edu/pub/whatever/
> /foobar.tar.gz, Netscape logins for you as "anonymous" and talks
> FTP directly. When I go to http://sunsite.unc.edu/pub/whatever/
> /foobar.tar.gz, in order to the file, it is downloaded via http,
> (normally through port 80), right?
This is correct.
> So, in Curt's scenario, the
> following happens:
>
> Netscape ---> via http to/from ---> proxie translates --->
> ---> via ftp protocol to/from ---> target site
>
> I do not understand how a proxie is so intelligent as to
> translate protocols.
Because it was programmed to do this. :-) The protocol `translation'
is not hard, actually.
In more detail, netscape opens up a connection to the appropriate
port (let's say 80) on the proxy, and passes it the following URL:
ftp://ftp.sunsite.unc.edu/pub/whatever/foobar.tar.gz
Note that this is a request for an FTP URL, but it uses the HTTP
protocol to make that request.
The proxy then opens up an FTP connection, using the FTP protocol,
to sunsite, and starts downloading the file. As it downloads, it
sends the file back to Netscape using the HTTP protocol.
cjs
Curt Sampson cjs@portal.ca Info at http://www.portal.ca/
Internet Portal Services, Inc. Through infinite mist, software reverberates
Vancouver, BC (604) 257-9400 In code possess'd of invisible folly.