The server gets definitions updates using Live Update or an file, and then automatically distributes the definitions to each of its clients on the network.
Read the following document for an overview and instructions: Live Update is a program that connects to a server, downloads the latest definitions, and applies the definitions to the computer on which it is running.
The VDTM is a fully automated solution for virus definitions distribution, and is enabled by default between servers and their managed clients.
With the VDTM, it is only necessary to update one server in order to update all computers in the network.
Live Update can retrieve definitions files either from the Symantec server (which it does by default) or from an internal Web, FTP, or file server created with the Live Update Administration Utility.They include the newest publicly available definitions.NOTE: Using pre-release definitions can result in incorrect detections and other unexpected results. These updates are designed to protect you from network threats, including exploits as they are transmitted.A manually triggered update immediately downloads and applies the latest definitions.This process might also address problems with automatic updates.