Linode.com Forum

[dgraham]

Hi,

I recently just started setting up my server. I installed Ubuntu 6, iptables and proftpd following this tutorial: http://ubuntuforums.org/showthread.php?t=79588

I followed the instructions for setting up ftps as described in that link, but unfortunately, I cannot seem to use ftps. When I try to connect, it logs me in fine, but denies me a directory listing. Using regular unencrypted ftp works perfectly, however.

Does anyone maybe have any thoughts?

Thanks a lot,

-Dougal

[pclissold]

Possibly a firewall problem?

FTPS and firewalls do not play nicely. The control connection happens on a well-known port, so you can log in OK. The data connection is a problem for FTP-aware firewalls. In a regular FTP session, the firewall can inspect the FTP server's responses on the control connection to a client's PASV or PORT command, and thus know which on which ports/addresses the data connection will be established. In an FTPS session, the control connection messages are encrypted, so the FTP-aware firewall cannot peek. Hence, it cannot know which on which ports the data connection will be established.

If this is the case for you, the firewall needs to be configured to allow a range of ports which are then set in proftpd using the PassivePorts directive.

[dgraham]

Awesome, thanks a lot! I opened those ports for and set the passive ports and it works like a charm, thanks a lot.

-Dougal