Lockdown mode disables direct host access requiring that admins manage hosts from vCenter Server. However, if a host becomes isolated from vCenter Server, the admin is locked out and can no longer manage the host. If you are using normal lockdown mode, you can avoid becoming locked out of an ESXi host that is running in lockdown mode, by setting DCUI.Access to a list of highly trusted users who can override lockdown mode and access the DCUI. The DCUI is not running in strict lockdown mode.
From the vSphere Client select the ESXi Host and go to Configuration >> Advanced Settings. Select the DCUI.Access value and configure it to root.
From a PowerCLI command prompt while connected to the ESXi host run the following command:
Get-VMHost | Get-AdvancedSetting -Name DCUI.Access | Set-AdvancedSetting -Value 'root'
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system VMware.