Multicasting is the way to use ZfD imaging services for mass reimaging with the least amount of overhead. It is useful if you have one computer with a clean software configuration that you want to clone on several other machines without having to prepare an image or CD, and without having to install or configure any ZfD software on a server or on the target computers.
With multicasting, all you need is a physical network with modern routers and switches and two ZfD imaging boot diskettes, which are very easy to prepare. The computers that will be imaged must be physically connected to the network. They can be computers with existing operating systems of any kind, or they can be brand new computers with no operating system installed.
One significant limitation of using multicast without installing any ZfD software is that it results in a set of computers that have duplicate network identities---the IP addresses, Computer (NETBIOS) names, Workgroup memberships, and Security Identifiers (Windows NT/2000 only) are all the same and thus will cause conflicts if deployed on the network without change.
For a handful of computers, this might not be a problem. But for a larger number, if the computers have Windows, we recommend that you install the ZfD imaging agent on them before doing the multicast. (You can use an Application object to do this easily. See Installing the Imaging Agent to Safeguard Workstation Identity Data in Setting Up Workstations for Imaging in Workstation Imaging in Deployment.) The imaging agent saves off the computer's network identity settings before the multicast session and restores them afterwards.