Reverse Proxy FTP traffic

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.

Answer

There are several ways to solve this problem. I like this setup:

                      +-------------+  
                      |  Gateway    |
                      |  NAT/Router |
                      |  216...     | 
                      +--+---+------+
                         |   |  
         +-- FTP ports --+   |       

         |                   |               
         |               Web ports
         |                   | 
    +----+--------+     +----+---------+    
    |  VM2 - FTP  |     |  VM1 - web   |    
    |  192...2    |     |  192...1     |      
    |  mounts     |     |  mounts      |    
    |   /www      |     |   /www       |    
    +-------------+     +--+--------+--+              
                           |        |                       

                     dom1 app proxy |                          
                           |        |
                           |  dom2 app proxy
                           |        |
                           |        |
                 +---------+---+ +--+----------+
                 |  VM3 - dom1 | |  VM4 - dom2 |
                 |  192...3    | |  192...4    |                 
                 |  mounts     | |  mounts     |
                 |  /www/dom1  | |  /www/dom2  |

                 +-------------+ +-------------+                                    

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.