Enabling lockdown mode disables direct access to an ESXi host requiring the host be managed remotely from vCenter Server. This is done to ensure the roles and access controls implemented in vCenter are always enforced and users cannot bypass them by logging into a host directly. By forcing all interaction to occur through vCenter Server, the risk of someone inadvertently attaining elevated privileges or performing tasks that are not properly audited is greatly reduced.
From the vSphere Web Client select the ESXi Host and go to Configure >> System >> Security Profile. Click edit on 'Lockdown Mode' and set to Enabled (Normal or Strict).
From a PowerCLI command prompt while connected to the ESXi host run the following commands:
$level = 'lockdownNormal' OR 'lockdownStrict'
$vmhost = Get-VMHost -Name
$lockdown = Get-View $vmhost.ConfigManager.HostAccessManager
Note: In strict lockdown mode the DCUI service is stopped. If the connection to vCenter Server is lost and the vSphere Web Client is no longer available, the ESXi host becomes inaccessible.
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system VMware.