Information
Audit DCUI timeout value.
DCUI is used for directly logging into ESXi host and carrying out host management tasks. The idle connections to DCUI must be terminated to avoid any unintended usage of the DCUI originating from a left over login session.
Solution
From the vSphere Web Client select the host, click "Manage" -> "Settings" -> "System" -> "Advanced Sytem Settings". Enter "UserVars.DcuiTimeOut" in the filter. Click edit and set the value for this parameter to 600 or more restrictive.