Re: Microsoft FTP and Linksys BEFSR41 (okay, Kerio 2.1.5 also)

From: Maxime Ducharme (maxime_at_pandore-designSPAMISBAD.com)
Date: 09/12/03 

Date: Fri, 12 Sep 2003 17:21:42 -0400

This is a passive / active connection issue.

The best way from my point of view is to properly
configure PASV on your server, and ask people to use PASV
mode.

If the client has a router which isnt well implemented for FTP
and ask a active connection, the server must connect to the
client on a port given in the ftp PORT command from port 20.

ftpserver:20 -> client:highport

If the router is dumb, it will drop incoming connections on high ports
and the client wont see any dir listing and wont be able to download
anything even if the client send the command with the correct filename.

Here what I suggest :
1. get a FTP server which permits to set listening ports for PASV

2. Configure the FTP server to listen on these ports
(e.g. 50000 to 50049)

3. Map these ports on the router to the FTP Server

4. Tell all clients to use PASV options

What will happen then is the client will connect to the FTP
via port 21 (control connection of FTP protocol)

When it will ask for a dir listing, the server will tell the client
via a PASV command on which port to connect to.

The client will connect on one of the ports set for PASV which
is correctly forwarded.

The client doesnt have to open any ports on his side and will be
able to see listing and download files.

If it doesnt work, re-read http://www.linksysftp.org ;-)

Ciao

---------------------------------------------------------------
  Maxime Ducharme
  Administrateur reseau, Programmeur
  Pandore-Design [http://www.pandore-design.com]

"CyberDroog" <CyberDroog@starfleet.gov> wrote in message
news:hcb4mv45l4g4qcc01ivhaf48qb871ruu4k@4ax.com...
> On Fri, 12 Sep 2003 16:38:35 GMT, Duane Arnold <notme@notme.com> wrote:
>
> >Well, guy what can I say? I use MS FTP on my Win 2K machine port
> >forwarding 20 and 21 on the 11S4 router and it works. It has been at
> >least 6 months ago that I used it. And this is on an 11S4 v1 router with
> >firmware 1.44. It doesn't have SPI and the Block Wan Request is enabled.

> >There must be something simple that's preventing it from happening for
> >you.
>
> Actually maybe it isn't so simple. Depending on the ftp client I use, it
> can seem to connect. There is just no file listing.
>
> ---
> LAWYER, n. One skilled in circumvention of the law.
>
> - Ambrose Bierce
>

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