I thought I had IPMI setup successfully and certainly appeared to have. My cluster is running vSphere 5.1 and had two hosts in standby mode under DPM. An VMware Update Manager scan today tried to wake up the two hosts and both failed. I KVMed into one of the UCS blades and started it, thinking vCenter would detect the blade was now on and out of Standby; no such luck. I was able to move the host/blade into and out of maintenance mode but I am really wondering what could have gone wrong. In order to setup DPM you have to have been able to put the blade into and out of Standby mode so this did work but I'm quite baffled by what has gone wrong now.