This one has me stumped.
Some weeks back it came to my attention that machines across the school were failing to wake up in the morning before school. No changes had been made on the network that I can think of.
On investigation I find that, if I run a WOL Packet Sniffer within Windows on a client machine and send a WOL magic packet to it from another PC/server, the packet is received successfully.
However, if I shut down the client and and then send the magic packet again, the client fails to wake up although WOL is enabled in the BIOS. This behaviour is replicated across all machines on the network.
I can only assume that a setting in our core switch is causing this but I don't understand how a WOL magic packet can be successfully delivered when a client is switched on, but not when it's off.
All our switches are HP Procurve and the core is a 5406zl model.
Any ideas gratefully received!
Have you tried WOLing a client on the same physical network segment to make sure that it works? Maybe just use a hub rather than a switch.
If it does work (from switched off), move the client further away to try to determine what is gobbling up the packets.
Thanks for the suggestions.
Yes, NIC settings have WOL enabled and when clients are shutdown the NIC lights remain active.
I will try connecting devices to a simple hub and see if the behaviour changes.
Not that i think this is happening at your site but we have had some computers refuse to WOL and it usually came down to either PSU or Motherboard being the issue. As you seem to have a problem with all your computers i cant see it being a hardware issue with your computers.
So it would seem that the WOL issue on my network is being caused by the Intel NIC drivers installed on 99% of our machines. On driver version 188.8.131.52 WOL worked successfully but since changing to version 184.108.40.206 (required for new hardware) WOL is not working despite it being enabled in the BIOS and within the NIC properties. A couple of forums suggest that registry hacks are required to get it working but I can't find any documentation about this.
Has anyone else seen this issue?
Registry hack? Surely Windows is not running if you want to WOL!
I would tend to agree but RM have suggested it has been required in order for it to work on the older driver...
I have tried this on the newer driver but predictably it doesn't work.The driver we released for this mainboard has a registry update that enables WOL and this is run from a script as part of the build process
Below are the regkeys which get merged. You could try added them but you will need to ensure the correct class is modified but as the driver has not been released by us but from intel I cannot help with this and cannot guarantee whether it will work.
gybe78 (18th May 2010)
No, not ideal at all - you're not wrong!
I recently solved this issue and wrote a procedure for my IT team on this, related to Windows power management of the NIC's. Setting the BIOS to accept magic packets is one thing, for sure, but preventing Windows from putting the NIC to sleep is often overlooked, and it is easy to deal with, as follows:
Steps to Disable NIC Power-Saving Features to Keep the NIC Awake
by Dan Reams
These steps are based on my experience and not by any one article read in the MS Knowledge Base or on the forums.
• Explore the power-saving properties of the NIC’s via their driver controllers (properties tabs) and de-select “Allow this computer to turn off this device”. You may have to hunt for this, in Windows XP, via right-clicking on the NIC, in Device Manager, or navigating to the NIC properties via the Network control. In Windows 7, there is often a “Power Management” tab associated with the NIC upon right-clicking the NIC’s properties via Device Manager. Related:
o Disable “Allow computer to turn off this device to save power”
o Windows 7 shuts off my network adapter when i the computer goes into - Microsoft Community
• Implement a catch-all registry setting value to over-ride any hidden “on” state of the power-saving feature. One can certainly navigate to the registry and create or edit keys, but I prefer to create registry files (.reg), for each NIC, and simply double-click them. This both avoids real-time typing mistakes and is much faster. In the below example, the 0001 represents NIC #1 in the system. If the system has multiple NIC’s, you should also create a .reg file with a value of 0002 in the same position.
Windows Registry Editor Version 5.00
Simply copy and paste the text above, to a text file, save it, and rename the file from .txt to .reg, then run it on the target PC’s. Again, if the PC has two NIC’s, create a version of the file that replaces 0001 with 0002 and run that as well.
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