[lug] Re: IP masquerading and FTP hangs up on ls

[Ferdinand P. Schmid]

Anthony:

I posted my response also to the blug list because I recently received
several requests regarding the same issue.  Hopefully in the future a
query on the topic will also list this response.

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

You can either try to set up your firewall to permit this incoming ftp
connection (painful) - or do the following:

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:
http://rpmfind.net/linux/RPM/contrib/libc5/i386/lftp-1.1.1-1.i386.html
Your passive mode command there is: <<set passive-mode on>>

Hope this will get you going,
Ferdinand

"Anthony N. Urwin" wrote:

>
> Hello,
>
>
>
> I saw your message about the ls command you had in a news group and
> you were getting invalid port command with IP masquerading
 I was
> wondering if you ran into a solution. I am having the same problem.
> Thanks in advance.
>
>
> Anthony N. Urwin
>
> mailto:anthony.n.urwin at udyne.com
>
> Udyne Systems Ltd.
>
>
> http://www.udynesystems.com/
>
> 1-716-393-0087
>
>
--
Ferdinand Schmid
(Staff Engineer)

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