By default, a ZENworks Primary Server will send all requests to the first Primary Server in its list of LDAP source servers unless those requests timeout, in which case it will send it to the next server.
Enabling LDAP Round-Robin on the Primary Server will cause all LDAP requests from the server to be equally balanced among all of its configured LDAP sources.
To enable LDAP Round-Robin, modify the following file:
Windows: %ZENWORKS_HOME%\conf\datamodel\authsource\authsourceconfig.xml
Linux: /etc/opt/novell/zenworks/datamodel/authsource/authsourceconfig.xml
In this file, change: <DoConnectionRoundRobin>false</DoConnectionRoundRobin> to <DoConnectionRoundRobin>true</DoConnectionRoundRobin> and restart the ZCM Services.