Session (Multicast) Mode (img session)

Use the Session (Multicast) mode to take an image of one workstation and put it down on multiple other workstations simultaneously over the network in a single operation.

For step-by-step instructions of the different ways you can perform multicast sessions, see the following sections:

For multicasting to work, each participating workstation must boot from an imaging device and run the imaging engine in this mode, as explained below. The workstation from which the image is taken is called the master, and the workstations that receive the image are called participants. Starting in ZENworks for Desktops 4, you can start the multicast session from the Imaging server. If you start the session this way, you specify an image file for multicasting rather than a workstation as the session master.

NOTE:  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.

Using the bash prompt, the following example explains the syntax and available parameters that you can use with the session parameter:

img session name [master|client] [clients=count [t=minutes]]
Parameter Specifies

name

The name of the multicast session. Each workstation joining the session uses the same value for this parameter.

NOTE:  The name must be unique among concurrent multicast sessions. It is hashed by the imaging engine to produce a Class D IP address for the multicast session. To facilitate troubleshooting (wire sniffing), all Desktop Management Workstation Imaging multicast addresses start with 231. For example, the session name doug produces the multicast address 231.139.79.72.

master|client

That this workstation is the session master or a session client.

If you omit this parameter, the imaging engine waits for a user on one of the workstations to press m to designate that workstation as the master, or for the imaging session to be started from the imaging server by selecting Manually Start Multicast, providing the required information, then selecting Yes.

clients=count

The number of participating workstations that must register with the master before imaging will begin. The option only applies for session masters.

If you omit this parameter, the imaging engine waits for the master user to press g. After imaging has begun, any participating workstations attempting to register are denied.

time=minutes

The number of minutes the master workstation waits for the next participant to register before starting the imaging process without reaching count registered participants. The option only applies for session masters.

If you omit this parameter, the imaging process won't start until count is reached or the master user presses g. After that, any participants attempting to register are denied.
Example Explanation

img session doug

Starts a multicast session named doug. Each successive workstation that issues this same command before the imaging begins joins the session. Imaging doesn't start until one of the users presses m to designate himself as master and presses g to start the imaging, or the imaging session is started from the Imaging server by selecting Manually Start Multicast, providing the required information, then selecting Yes.

img session doug m

Starts a multicast session named doug and designates this workstation as the master. Each successive workstation that issues img session doug before the imaging begins joins the session as a participant. Imaging doesn't start until the master user presses g.

img session doug master clients=5

Starts a multicast session named doug. Each successive workstation that issues img session doug before the imaging begins joins the session. Imaging doesn't start until one of the users presses m to designate himself as master, or until the imaging session is started from the Imaging server by selecting Manually Start Multicast, providing the required information, then selecting Yes. Five other workstations must also register as participants before the session begins.

img session doug master clients=5 time=20

Starts a multicast session named doug. Each successive workstation that issues img session doug before the imaging begins joins the session. Imaging doesn't start until one of the users presses m to designate himself as master, or until the imaging session is started from the Imaging server by selecting Manually Start Multicast, providing the required information, then selecting Yes. Either five other workstations must register as participants or more than 20 minutes must elapse between any consecutive participant registrations, whichever occurs first, and then the session will begin.