A vCenter HA cluster consists of three vCenter Server instances. The first instance, initially used as the Active node, is cloned twice to a Passive node and to a Witness node. Together, the three nodes provide an active-passive failover solution.
Deploying each of the nodes on a different ESXi instance protects against hardware failure. Adding the three ESXi hosts to a DRS cluster can further protect your environment.
When vCenter HA configuration is complete, only the Active node has an active management interface (public IP). The three nodes communicate over a private network called vCenter HA network that is set up as part of configuration. The Active node is continuously replicating data to the Passive node.
![The three-node cluster consists of an active, passive, and witness node. A private network is used for communication between the three nodes.](images/GUID-6CFBA1B3-43C8-4D82-9D4F-BB2B7C894DC9-high.png)
All three nodes are necessary for the functioning of this feature. Compare the node responsibilities.
Node | Description |
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Active |
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Passive |
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Witness |
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