[lug] Re: FTP/IP masquerading problem

Ferdinand P. Schmid fschmid at archenergy.com
Wed Feb 9 11:13:13 MST 2000

The problem is caused by a peculiarity of FTP:
Whenever you make a standard FTP connection to a host the host will try to establish
a second connection back to you for transferring information.
Since IP Masquerading only allows outgoing connections this incoming connection
won't succeed and you won't be able to do directory listings...

The way to deal with this is to use FTP in passive mode.  To do this you type the
command <<passive>> after you established an FTP session (=after you logged in to
the host).  That should get you going in regular ftp on UNIX type systems.
Microsoft's implementation of ftp doesn't have that option.  On MS systems you may
need to use Netscape, IE or a client like WS_FTP
(http://www.ipswitch.com/Products/WS_FTP/).  These improved ftp clients for Windows
cost money - but that's the Microsoft world's philosophy (you pay for software, no
matter how basic it is).
A nice ftp client for Linux is lftp because it allows mirroring of web sites...  You
can find that at:
Your passive mode command there is: <<set passive-mode on>>

Hope this will get you going,

"John W. Miller" wrote:

> Greetings,
> I read your news item concerning your problem with getting FTP to work behind
> IP Masquerading.  I am having the same problem.  Do you know how to solve the
> problem?
> I am runnin IPChains on Redhat Linux with kernel v2.2.5-15.
> Thanks for your help.
> --------------------------------------------------------------------------------
> John W. Miller                                     phone: (724)357-7851
> TSC, IUP, G20C Stright Hall                          fax: (724)357-4005
> Indiana University of Pennsylvania                 email: jwmiller at grove.iup.edu
> Indiana, PA  15705-1087
> --------------------------------------------------------------------------------

Ferdinand Schmid
(Staff Engineer)

Architectural Energy Corporation
2540 Frontier Avenue, Suite 201
Boulder, CO 80301
Phone: (303) 444-4149
Fax: (303) 444-4304
e-mail: mailto:fschmid at archenergy.com

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