Passive FTP?

[LordFortius]

Alright, I set up my internet router to send all traffic for ports 20 and 21 to a specific computer on the network to serve as an FTP server. It works well, except when I use an FTP client that wants to use passive FTP. Passive FTP just doesnt seem to work with this setup... is there some port number that I could open up that would allow it to work freely?

 

[LordFortius]

Bump

 

[Buddha Bart]

thats odd, typically its the reverse.

sorry, don't know enough about the difference to troubleshoot, but my understanding was that passive made the communication between hosts stick to one persistant connection, vs the multiple connections and port numbers of an active mode transfer.

*shrug*

bart

 

[bex0rs]

is there some port number that I could open up that would allow it to work freely?

Yes, sort of. Typically you can configure the ports that your FTP server will use for passive mode transfers. Unfortunately, your ftp server software, by default, chooses these ports (numbered > 1024) at random. I don't keep up to date with win32 ftp servers, but I do know that proftpd under *nix allows for "static" configuration of a range of passive ftp ports to allow for a situation like yours where ports need to be forwarded to another host. This is all due to the nature of passive ftp.

Assuming your server software supports that option, you'll also need to make sure that your gateway allows a range of ports to be forwarded. Again, I don't really keep up to date with windows nat software or the various standalone products available, but this is a fairly basic feature that should be supported.

What's wrong with your clients using active ftp?

~bex0rs