FTP and SSL

Stumbled across some great articles about FTP, SSL and Active/Passive settings made by Alun Jones (Security MVP).

• How FTP Data Connections Work Part 1 (OR: Don’t Open Port 20 in your Firewall!)
• How FTP Data Connections Work Part 2 (OR: Fun With Port 20)
• FTP 7.5 + SSL + Non-default port / AspNetAuth

Thanks to Steve Schofield for the reference.