Invalid IPMI MAC Address

I really like the DPM (Distributed Power Management) feature of vCenter, it allows us to save money during periods of low load on our VMware Clusters. We use Windows Datacenter Edition processor licenses to license all the virtual machines on the clusters under a Microsoft SPLA  (service provider license agreement) agreement.  During these quieter spells DPM shuts off the servers and if they've been off for the whole previous month then we know that no windows VM's have been on the hosts, thus saving licenses.

DPM allows configuration of DRAC's, ILO's or any IPMI device, the configuration is done in vCenter - Host - Configuration - Power Management - Properties

On the Dell M1000e blade Chassis, there is a firmware issue whereby the CMC and iDRAC's web pages aren't reporting the correct MAC address. This issue is actually fixed on a later firmware version, but as yet haven't found time to get this updated.

Enter the username, password, IP and 00:00:00:00:00:00 as the MAC address

To find out the correct MAC address on the vCenter server locate the logs folder

C:\Users\All Users\VMware\VMware VirtualCenter\Logs

Look for the latest vpxd-******.log and open it in notepad and search for 00:00:00:00:00:00. This should reveal the line

[2011-11-22 15:02:21.980 05384 info 'App' opID=19A6861D-00002EF0] [VpxLRO] -- ERROR task-723258 -- host-294277 -- vim.HostSystem.updateIpmi: vim.fault.InvalidIpmiMacAddress:
Result:
(vim.fault.InvalidIpmiMacAddress) {
   dynamicType = <unset>,
   faultCause = (vmodl.MethodFault) null,
   userProvidedMacAddress = "00:00:00:00:00:00",
   observedMacAddress = "a4:ba:db:00:20:94",
   msg = "",
}
Args:

Arg ipmiInfo:
(vim.host.IpmiInfo) {
   dynamicType = <unset>,
   bmcIpAddress = "***.***.***.***",
   bmcMacAddress = "00:00:00:00:00:00",
   login = "root",
   password = (not shown),
}

Now add the observedMACAddress into the BMC MAC Address and all should go through correctly.