As I have mainly installed ESX servers, today I was posed with a situation where I needed to restart the management agents on an ESXi server. Immediatly I was thinking I would need to access the emergency service console etc but I found the convienent restart management agents option in the F2 menu.
To access do the following
1. From the console screen (use ilo / drac connection to connect if needed) press F2
3. Now press F11 to restart the agents
You can now logout again, this is a usual one to resolve a host that is appearing as disconnected and you are unable to manage it.