[lug] SSH Tunneling FTP

[Warren Sanders]

On Fri, 9 Feb 2001 rm at mamma.varadinet.de wrote:

> Date: Fri, 9 Feb 2001 00:27:18 +0100
> From: rm at mamma.varadinet.de
> Reply-To: lug at lug.boulder.co.us
> To: lug at lug.boulder.co.us
> Subject: Re: [lug] SSH Tunneling FTP
>
> On Thu, Feb 08, 2001 at 04:14:53PM -0700, Warren Sanders wrote:
> > I'm trying to port forward FTP on a Windaws box using SSH client PengiNet.
> > The registered version I have does port forwarding to or from remote
> > system.  By testing, I would disconnect the SSH connection to see if the
> > FTP would die.  In all tests, FTP continued as normal, proving the ports
> > were not forwarded.  I must not understand the concept.  So without going
> > into a lot of detail on what all I did, could someone explain some do's
> > and don'ts of port forwarding?
>
> What exactly do you mean by '... continued as normal'. Can you still send
> out commands like 'dir' to the server or do you mean that the data is
> still comming in. The late is normal, since ssh only tunnels the control
> channel but _not_ the dat channel. FTP works with two tcp connections,
> one to issue commands and the other(usually opened from the server back
> to the client unless you use the PASSIVE command) to send data.


Continued normal... meaning the data was not broken, I was uploading at
the time. I was using PASSIVE mode BTW.


>
> > In a nutshell, I would forward port 21 to say 4421 on the SSHd and FTPd
> > destination.  Also tried forwarding SSHd FTPd destinations 21 to local 21
> > but that produced a binding error due to it already being use.
>
> Port 21 is the control channel ...
>
>
>  Ralf
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-- 
Warren Sanders
http://MontanaLinux.Org