Okay so Google is letting me down just due to the sheer volume of stuff related but not specific to my problem that I could find.
I have a c# program that connects to various ftp sites and downloads the info then dumps it into a database for me. On server 2003 r2 I have no issues with this program running. Due to the situation, I am having to locate this code to windows server 2008 r2. It works fine as far as running but it had issues connecting to the ftp sites. I opened port range 20-21 as a custom incoming and outgoing rule in windows firewall. Now some of the sites connect but it seems some are still timing out. Where as if I open all ports everything seems to work fine, but that's a security risk I am not willing to live with.
Should opening that range of 20-21 be sufficient to allow the ftp connections or is there something else I am missing.