Encountered an interesting issue when adding Power Management settings on one VMware ESXi 5.1 host today when vCenter Server returned an error message that the BMC MAC Address was invalid. The interesting thing was that I did check the Mac address prior to entering it in VMware vSphere Client and as such should have been correct.
After digging trough the vCenter Server logs, located in a vCenter Server 5.1 installation: c:\ProgramData\VMware\VMware VirtualCenter\Logs\vpxd-nnnn.log
2013-11-07T15:27:50.774+02:00 [02336 info 'Default' opID=9C1D4C61-00000189-b8] [VpxLRO] -- ERROR task-156890 -- host-41994 -- vim.HostSystem.updateIpmi: vim.fault.InvalidIpmiMacAddress:
--> Result:
--> (vim.fault.InvalidIpmiMacAddress) {
--> dynamicType = <unset>,
--> faultCause = (vmodl.MethodFault) null,
--> userProvidedMacAddress = "BC:30:XX:XX:XX:XX",
--> observedMacAddress = "5c:f9:XX:XX:XX:XX",
--> msg = "",
--> }
--> Args:
-->
After copying the observed Mac Address and using this for the value, the host was able to save the required Power Settings.
