installer, you are prompted to select "managed" or "unmanaged". If you select "managed", you have to specify a server name at that time or copy a sylink.xml file later (only two of a few possibly ways) to redirect it to a server.
Does it have a 'green dot' on the shield icon? If not, then it is not managed, and it is pointing towards the default Symantec Liveupdate site for definitions.