Manage ESXi Lockdown Mode from DCUI

If your VMware ESXi 4.0 & 4.1 servers are joined in VMware vCenter Server infrastructure then you can enchance security for these hosts. Follow on VMware Security Hardening you need to enable Lockdown Mode to restrict root access (HCN02 requirement).

Lockdown mode forces all operations to be performed through vCenter Server (you can continue to use Direct Console User Interface aka DCUI to manage host).

VMware Security Hardening guide notes that lockdown mode can be enabled or disabled in two places:
• In the vSphere Client, when connected to the vCenter Server managing the host
• In the DCUI of the host

In ESXi 4.0:
To check if Lockdown mode is enabled, run the command:
vim-cmd -U dcui vimsvc/auth/admin_account_is_enabled

To disable Lockdown mode, run the command:
vim-cmd -U dcui vimsvc/auth/admin_account_enable

To enable Lockdown mode, run the command:
vim-cmd -U dcui vimsvc/auth/admin_account_disable

In ESXi 4.1:
To check if Lockdown mode is enabled, run the command:
vim-cmd -U dcui vimsvc/auth/lockdown_is_enabled

To disable Lockdown mode, run the command:
vim-cmd -U dcui vimsvc/auth/lockdown_mode_exit

To enable Lockdown mode, run the command:
vim-cmd -U dcui vimsvc/auth/lockdown_mode_enter

See VMware kb to more details