FTP Problems

I am having problems with ftp

Our customer is able to login to our site from a unix server but they can't get the file, the process just hangs until they terminate it. The same thing happens if they try a dir, they don't get any data returned.

They can get the file if they do it from a windows pc, through FTP DOS and Internet Explorer

Maybe it could be port translation that is causing the problem ?

Our firewall is open for port 21 only for our ftp server.

Does this ring any bells with anyone ?

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What type of firewall are you using?

What FTP server are you using?
Try set the PASV mode for transfer
stevendunneAuthor Commented:
FTP problems with cust1, cust2 & cust3 ?  Basically they were unable to complete the data connection into our FTP server, the connection just locked up.  I tried all sorts including opening up our firewall for high-ports, ftp ports 20 & 21 for there specific FTP IP addresses.  This still didn't resolve the issue.
I found a setting in the firewall which "Forces Inbound & Outbound FTP traffic to default to Port 20".  This then resolved the above problem for these 3 customers.
However, this has had a knock on affect with cust4, where we send the file across into there FTP site. The same is now happening here, the data connection is locking up my end when I try to connect.  They are using "Active" FTP which worked fine, before I setup the "Forces Inbound & Outbound FTP traffic to default to Port 20" setting.  However if I remove this setting it will effect cust1, cust2 & cust3.
Cust4 are using active ftp, I found these links.........
I've even enabled the "H.323 transformation" setting under Dynamic Ports to help with video & more specifically data connections.

Any ideas ?

Your cust1,cust2,cust3 are connecting to server behind firewall and they uses PASSIVE metod

Setup your server to accept Passive requests and set a port range for passive connection (example: 40000-49999)

If server resides in DMZ, then check your firewall rules and set these:

Deny    all/all                    from   WAN/*  to   DMZ/*              <-- deny everything from WAN
Allow   tcp/21                   from   WAN/*  to   DMZ/ServerIP    <-- enable only ftp to server
Allow   tcp/40000-49999    from   WAN/*  to   DMZ/ServerIP    <-- enable ftp passive ports to connect
Allow   tcp/20                   from    DMZ/*  to   WAN/*              <-- enable connecting from DMZ (for active ftp connections)


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