Make sure that the firewall allows the LiveUpdate executable to connect to the Internet through the correct ports and that the firewall allows connections to the correct domains. Read your firewall's documentation or contact the manufacturer to find out how to confirm these settings.
*.LiveUpdate connects over TCP ports 80 (HTTP), 21 (FTP) and 443 (HTTPS).
*.The file that connects to the Internet is LuComServer_*_*.exe in LiveUpdate 2.5 and later and Lucomserver.exe in LiveUpdate 2.0 and earlier.
*.The default folder for this file is C:\Program Files\Symantec\LiveUpdate.
*.LiveUpdate connects via HTTP to the domainsliveupdate.sym antecliveupdate.com, liveupdate.symantec.com, and akamai.net.
*.If a connection fails, LiveUpdate tries to connect to one of the other listed domains. The listed domains may change because of server maintenance.
*.If LiveUpdate cannot make an HTTP connection, LiveUpdate connects via FTP to update.symantec.com/opt /content/onramp.
How to determine whether your firewall is blocking LiveUpdate
Article:TECH139451|Created: 2010-09-09|Updated: 2011-08-26|Article URL http://www.symantec.com/docs/TECH139451