We have hosted infrastructure in the US and UK which both needed FTP access. Previously FTP in IIS has been pretty straightforward, but given the setup of each environment FTP was going to be an issue.
I found the following walkthrough given by Microsoft, as we were using Windows Server 2008 R2, the installation of the additional module can be ignored: http://learn.iis.net/page.aspx/309/configuring-ftp-firewall-settings-in-iis-7/
The one caveat for me given our environment was the step whereby you specify the ‘External IP Address of Firewall’, for the environment behind a load balancer, this must be specified. When behind a firewall, at least in our instance, nothing should be specified.
The symptoms of issues were being able to log into the FTP server, but then not being able to list the directory, in both passive and active modes on the client side, it would just time out.
So if you’re seeing a timeout when you list directory from your FTP client connecting to an IIS 7.5 FTP server, tweak the settings specified in the link above. In both cases, I had to specify a data channel port range.