Re: FW: cant use "ls" from command line

[Kalum / Grendel <kalum lintux cx>]

On  Sun, 25 Mar 2001, David Thomas commented thusly,

> I have a windows machine able to browse the internet via my linux box and
> can also browse FTP via HTTP but when it comes to using a DOS prompt on the
> windows box then I can FTP to the site but cannot use "ls" as this causes
> the FTP session to "hang",

When you use a command like ls, or try ot upload or download files it
involves either the client or the server initiating a connection to the
other.

Traditionally what happens is that many ftp programs use the PORT command
and the server makes the data connection to the client program and
transferes data (ls command etc) to the client, as you can see this may
not work when very restricted firwewalls are run on the client side or
when confusing MASQ setup is in place. 

So when the client is behind restrecited firewalls it is better to use the
PASV command which causes the Client to make the connection to the server
based on the servers return information, which means that this will work
when complex firewalls and MASQ is on the client side.

So what I think is hapenning is this, your windoze ftp program is using
PASV which means that the client program makes the connection to the ftp
server which is ok and fine.

But the dos ftp program is using the PORT command, and it send information
to the ftp server to say connect to ip address 132.233.32.3 at port 2318 ,
and then the remote ftp server tries to make the connection but due to a
wrongly setup IPMASQ, or a problem with MASQ it self, somehow the
connection never arrives at your windoze box :( so your dos ftp program
will keep on waiting for the ftp server to connect to it, which never
happens because either due to the firewall or MASQ the server cant connect
to your dos ftp client.

So what I would advice you to do is to try this, get your dos ftp program
to use PASV instead, there should be a commandline option in that shitty
app to make it use PASV, so please try that, if there is no such a option
say a big fsck you to microsofts ftp program and get a better one for
dos, there are hundreds of them out there, ncftp is a good one.
ftp /? should give you the list of options I think.

> I have got the basic rc.firewall script running
> and for all other purposes then that is running fine, is there any modules
> etc that I need to include to get ls working via a DOS prompt?? I can use ls
> fine to the site from the Linux machine...but it is just the windows machine
> causing a problem, "dir" also has the same effect, 

dir also involves the server or client making a connection to one another.

> then I dont have any problems, it is noly when going through IP MASQ/IP
> Forwarding that I am having problems...

Exactly, sorry for not being more informative but I think you must check
your MASQ setup, this is personally not my avenue butI hope you can get
things figured out.  

Please tell me how things go. 

Best Wishes,
Grendel


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