To multicast an image is to take an image of one workstation (the master), immediately send it over the network to multiple other workstations (the participants), and put it down simultaneously on those workstations. You can specify a workstation as the session master, or you can specify an image file that you have previously saved and customized.
If the session master is a workstation, a base image is taken of all partitions on the hard disks and other storage devices (such as Jaz drives) of that workstation.
Before the image is put down on the participating workstations, all existing partitions are removed from the hard disks and writable storage devices of those workstations.
For multicasting to work properly, the routers and switches on the network must have multicast features configured. Otherwise, multicast packets might not be routed properly.
In versions of ZENworks for Desktops prior to 3.2, the master had to be a Linux workstation, which formerly restricted multicasting to exact “cloning” of the workstation.
Multicasting is the way to use ZENworks Desktop Management Imaging services for mass re-imaging with the least amount of overhead. It is useful if you have one workstation with a clean software configuration that you want to duplicate on several other machines, or if you have a single image that you want to set up on multiple machines.
With multicasting, all you need is a physical network with modern routers and switches.
If you are setting up multicasting by visiting each workstation, you also need an imaging boot CD or DVD, or the workstations must be PXE-enabled. For more information, see Section 55.0, Preparing an Imaging Boot Method.
The workstations to be imaged must be physically connected to the network. They can be workstations with existing operating systems of any kind, or they can be new workstations with no operating system installed.
One significant limitation of using multicast without installing any ZENworks Desktop Management software is that it results in a set of workstations that have duplicate network identities. The IP addresses, Computer (NETBIOS) names, Workgroup memberships, and Security Identifiers (Windows 2000/XP only) are all the same and can cause conflicts if deployed on the network without change.
For multicasting with a handful of workstations, this might not be a problem. But for a larger number, if the workstations have Windows, you should install the ZENworks Imaging Windows Agent on them before doing the multicast. (See Step 3 of Section 57.2, Enabling a Windows Workstation for Auto-Imaging Operations.) The ZENworks Imaging Windows Agent saves the workstation’s network identity settings before the multicast session and restores them afterwards.