When you use the vSphere Client, the Set Up vCenter HA wizard creates and configures a second network adapter on the vCenter Server Appliance, clones the Active node, and configures the vCenter HA network.
Prerequisites
Verify that each host in the cluster has a vCenter HA port group added.
Determine the static IP settings for the two vCenter Server Appliance nodes that become the Passive and Witness nodes after configuration.