We are using a MS FTP Server with IIS 6.1. Our client has been running a FTP job weekly just fine for sometime with no connection issues. Last Thurs they all of a sudden cannot connect. No changes to the FTP server or Firewall were made to my knowledge. We have a NAT rule in place to allow ftp and route from the pub address to local server IP and have not had an issue until this past thursday. Im unsure what has changed but we get a error when trying to connect from outside as any users "PORT Command Failed Failed to retrieve directory"