I was wondering if anyone knew of a reverse proxy server to reverse proxy ftp traffic. I would like to run many servers on ip address, but then pass the traffic to an internal server with its own ip address. Thank you for any suggestions.
There are several ways to solve this problem. I like this setup:
The idea is that the gateway uses NAT and port-forwards the web and ftp requests to their respective VM's. The Web and FTP VM's use virtualhosts to manage the specific subfolders of /www based on requested domain. Then the web server proxies the dynamic content requests back the per-domain application VM's which only have access to their own sub-directory. There is also no reason you can't have the web server serving WebDAV as well.
We currently use JFTPGW - http://www.mcknight.de/jftpgw/
It has worked very well for us so far.
Here's the relevant section from my jftpgw config:
Why is a reverse proxy necessary? Have you considered using a Destination NAT? (DNAT)
If you run Linux, depending on your infrastructure, you should be able to configure NATs on your server. Your Linux server would have to be routing the traffic on the Internet routable IP to an internal network for this to be a functional solution.
If this is not helpful, you will need to provide additional details regarding your infrastructure for a more specific recommendation.
Network Address Translation will do what you describe. Either by specifying different ports or configuring virtual hosts in your FTP daemon, which most modern daemons support.