You can check it from the sylink log
Title: 'How to confirm if Clients are receiving LiveUpdate content from Group Update Providers (GUPs)'
Document ID: 2009110311145748
> Web URL:
http://service1.symantec.com/support/ent-security.nsf/docid/2009110311145748?Open&seg=ent
or
On the client, look in the registry under
HKEY_LOCAL_MACHINE\Software\Symantec\Symantec EndpointProtection\LiveUpdate.
Check the settings for the following keys:
■ UseLiveUpdateServer
If this key is set to 1, the client uses an internal LiveUpdate server or Symantec
LiveUpdate directly.
■ UseManagementServer
If this key is set to 1, the client uses the management server.
■ UseMasterClient
If this key is set to 1, the client uses a group update provider