Make the following change to the LiveUpdate policy:
Policies > LiveUpdate > LiveUpdate Settings policy > Edit the policy
By default, "Use the default management server (recommended)" is checked,uncheck "Use default Symantec LiveUpdate server
How client computers receive content updates
Managing content updates
See below thread
https://www-secure.symantec.com/connect/forums/how-force-client-take-update-sepm-server-onlyno-internet-update