Hi Dan, how are you?
LiveUpdate connects over TCP ports 80 (HTTP), 21 (FTP) and 443 (HTTPS).
Also connects via HTTP to the domains liveupdate.symantecliveupdate.com, liveupdate.symantec.com, and akamai.net.
Please take a look into this article for more informations.
How to determine whether your firewall is blocking LiveUpdate
http://www.symantec.com/business/support/index?page=content&id=TECH139451
I hope that helps
Thank You
Lucas