check this link to answer your question
http://www.symantec.com/docs/TECH97397
Symantec makes LiveUpdate content available on the Internet through a partnership with the Akamai server network. Akamai is a network of tens of thousands of servers scattered worldwide for more efficient distribution of content. Symantec recommends specifying Symantec LiveUpdate servers via DNS name (fully qualified domain name), not via one or more static IP addresses. Use of static IP addresses to access Symantec LiveUpdate content is not supported or recommended