Does FileConnect use a standard FTP port for the Managed Download?
FileConnect uses Port 21 to download product upgrades. Note Symantec recognizes that opening any firewall port can be a security risk for your network. Port 21 is a standard port for FTP traffic. If you want to maintain a secure network environment with regards to FTP, you may want to either open this port for this download only, or download using the HTTP protocol.