Novell FTP behind NAT - Problem seeing files from FTP client

[snorkel]

At my company, we have recently built an FTP server on Netware 6.5 SP2.
We have no problems with internal connectivity or functionality of the
server. To facilitate external connectivity for other companies to send and
recieve data from our FTP server, we have implemented a NAT enabled router.
The router is configured to (through NAT) forward all communication to the
internal IP of the FTP server when someone uses FTP to access the external
IP of the router. Connectivity works fine. From the outside (the internet)
you can FTP to the external (pulic) address, and you are prompted for
username and password and if entered correctly you can log in to the
internal FTP server. So far, so good - but....

When using many client softwares, or even just from the command line from
internet hosts, there is a problem. Clients will allow you to move file
back and forth, but they do not list the files in the directory after you
authenticate. From the command line, if you do an "ls" or a "dir", (passive
mode by default) the contents of the directory are never displayed and the
FTP connection times out.

Can anyone help, or provide suggestions?

Thanks...

 

[marvhuffaker]

You have to remember that there are 2 ports you need to get FTP working correctly. One is for Authentication/control and the other is for data transfer (or something along those lines).

So you need to make sure you have both port 20 and 21 configured through your firewall. Look at this link, they have it diagrammed really nicely.

http://slacksite.com/other/ftp.html

Marvin Huffaker MCNE, CNE
Marvin Huffaker Consulting

http://www.redjuju.com