Virtualization, Cloud, Infrastructure and all that stuff in-between

My ramblings on the stuff that holds it all together

vSphere Host cannot enter Standby mode using DPM and WoL


I encountered this error in my lab recently, I previously wrote about how I was able to use DPM in my home lab, I’ve recently re-built it into a different configuration but found that I was no longer able to use just Wake on LAN (WoL) to put idle cluster hosts into standby.

I got the following error, vCenter has determined that it cannot resume host from standby.

Confirm that IPMI/iLO is correctly configured or, configure vCenter to use Wake-On-LAN.


1st thing to note is that there is nowhere in vCenter to actually configure Wake-on-LAN, however you can check to see which NICs in your system support Wake On LAN (not all do, and not all have WoL-enabled vSphere drivers)

My ML115 G5 host has the following NICs

  1. Broadcom NC380T dual port PCI Express card – which does not work with Wake on LAN
  2. Broadcom NC105i PCIe on-board NIC which does support WoL.


In my current configuration the onboard NIC is connected to a dvSwitch and is used for the management (vmk) interface


This seems to be the cause of the problem because if I move the vmk interface (management NIC) out of the dvSwitch and configure it to use a normal dvSwitch vSwitch DPM works correctly.

In a production environment a real iLO/IPMI NIC is the way to go as there are many situations that could make WoL unreliable. However, if you want to use DPM and don’t have a proper iLo you need to rely on Wake-On-LAN so you need to consider the following..

  1. you need a supported NIC
  2. you need a management interface on a standard vSwitch, connected to a supported NIC

Also, worth noting that if you are attempting to build a vTARDIS with nested ESXi hypervisors you cannot use DPM within any of your nested ESXi nodes, the virtual NICs (e1000) do support WoL with some other guest-types like Windows, so your VM guests can respond to WoL packets (via the following UI screens)


However the e1000 driver that ships with vSphere ESX/ESXi does not seem to implement the WoL functionality so you wont be able to use DPM to put your vESXi guests to sleep – kind of an edge-case bit of functionality and ESX isn’t an officially supported guest OS within vSphere so it’s not that surprising.

One response to “vSphere Host cannot enter Standby mode using DPM and WoL

  1. David Hill February 10, 2011 at 3:26 pm

    Hey Simon

    Found an error on your post and I have updated below:

    This seems to be the cause of the problem because if I move the vmk interface (management NIC) out of the dvSwitch and configure it to use a Standard vSwitch DPM works correctly.

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