If an MDM Server can be contacted using multiple DNS names, then you can specify the default DNS name that mobile devices will use to communicate with the MDM Server. To set the default DNS name, select the Primary Server that has the MDM role assigned and navigate to Settings > Infrastructure Management > Default DNS Name. You can select the default DNS name from the drop-down list displayed on this page.
ZENworks detects all the network interfaces that are attached to the MDM Server with the corresponding DNS names. The drop-down lists the DNS names along with the Additional DNS Names configured for the Primary Server.
If the default DNS name is modified, then you might have to remint the Primary Server certificate so that the newly configured DNS name is also part of the server certificate that mobile devices will use while enrolling to the zone.
IMPORTANT:Before a certificate remint, ensure that you include all the DNS names in the Additional DNS Name settings in ZCC (Configuration > Management Zone Settings > Infrastructure Management > Additional DNS Names).
Also, if mobile devices are enrolled to this Primary Server, re-enroll these devices if the previously configured DNS name is not reachable anymore. You might have to re-publish any assigned Mobile Email Policies so that the new DNS name setting takes effect.