Knowledgebase Article

Setup the ftp server to operate behind a router or firewall device

INTRODUCTION

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The information in this article applies to:

All versions of BlackMoon FTP Server

SUMMARY

To setup your FTP server to work correctly behind a router or firewall, you must configure your router or firewall and enter a few settings in the server options to make it aware of your special situation. This article assumes your router is properly setup. Instructions on how to setup your router of firewall is not not covered here. Contact your router manufacturer for that

MORE INFORMATION

Firewalls, routers and NATs allow you to do cool things like secure your computer or even share internet access. They also have unintended side effects of making server applications not work without proper setup. If your computer is assigned an internal IP address by your router or NAT you have to setup the router/nat to forward ports that the FTP server uses to the computer the server is running on. Remeber when transferring in PASV (passive mode) the server selects a random port and tells the ftp client to connect to transfer data. If that port isn't open the transfer fails.

To set this up properly go into the blackmoon server options and click on the "defaults" tab. Check the "use passive host/ip" option and enter your INTERNET address. Then check the port range option and enter a port range to use for PASV transfers. Now go to your router/NAT/firewall setup and open/port forward that port range. This should solve the PASV problem many people have. Remeber if the ftp client uses PORT (active mode) to transfer files and it doesn't work, then it's the clients fault.

Last Reviewed:9/13/2003 2:13:17 PM