Host monitoring is generally disabled during network maintenance activities that would affect the host's management network connectivity. This is done to prevent unnecessary triggering of the host isolation response configured for the HA cluster. Host monitoring can be disabled by editing the cluster settings.
The following procedure explains how to disable host monitoring:
From the vCenter's Home inventory, navigate to the Hosts and Clusters view.
Select the cluster and navigate to Manage | Settings | vSphere HA, and click on Edit.
Deselect the Enable Host Monitoring checkbox, and click on OK.
The runtime information for HA should now show the Host Monitoring value as Disabled.