WOL How do I do it?

I don't know what WOL means. But getting data from a PowerPC to an Intel Mac, you should follow these directions:

https://discussions.apple.com/docs/DOC-2295

If that's not what you mean, please spell out any acronyms, and exactly what you are trying to accomplish?

Before you consider Wake On Lan, remember, there is nothing that will stop a direct lightning strike from hitting your machine in terms of surge protectors/suppressors. It is better to have a remote backup somewhere, in case of theft. Your internet provider may offer some webspace to store files you need access to anywhere. http://www.zoho.com/ offers remote spreadsheet, calendar, and word processing free. Google Docs does presently, but a recent letter I got from them suggests that may be changing.

Apple menu -> System Preferences -> Energy Saver and sometimes the Security settings has wake on network access settings depending on the operating system.

And there are several Mac compatible solutions you can find on Google that have more sophisticated abilities.

No one here can comment on Apple's suggestions as far as "why" they make it. That would at least by some standards be trying to guess Apple's policy. I've simply offered my advice based on my 30 years of experience with computers. You can take it for what it is worth. Just search Wake On Lan Macintosh. Google must tie its searches now to a cookie even if you aren't logged into any of their services.

I think Apple broke the "magic packet" WoL facility in 10.7. I used it frequently in 10.5, and sending a magic packet from my MacBook to my Mac Pro would fully wake the sleeping Pro. I skipped to 10.7 on both machines, and now sending a magic packet to the sleeping Pro no longer wakes it. I'm really interested to know why Apple decided to break this functionality.

That's something you'll probably never get an answer to, unless you become an official developer on http://developer.apple.com/ if that is indeed true. I can't imagine if a feature is available in the System Preferences that it on its own is broken. It is possible your packets simply aren't getting through because the port mapping in your router isn't letting it get through. Make sure the port you would expect to wake it is open.

Here's what's going on: Apple changed the kernel's response to magic packets (the Ethernet WoL packet) so that, by default, the machine no longer wakes up fully when it recieves one; it stays in low-power wake. Instead, they want you to buy an AirPort or use another computer (a Bonjour Sleep Proxy) to watch the network for traffic trying to reach certain services on your sleeping machine, and to give it a kick (a WoL packet) when it sees such traffic. This kernel feature is called Dark Wake.

But that's annoying. Many things don't use mDNS, and many people aren't using Apple router products. I use SVN to sync things between my computers, so when my Mac Pro is asleep, I want to be able to wake it up from wherever I am and from whatever device/platform I'm using. So, I told the kernel not to use Dark Wake.

The kernel is the very first program that the boot loader (which is the first screen you see when you power on your computer -- probably grey and with an Apple logo) calls. The boot loader can pass arguments to it, much like other programs you might run from the command line.

Here's the procedure I used (please don't do this unless you're comfortable using vi to edit system files):

1. Opened a Terminal window.
2. Changed to /Library/Preferences/SystemConfiguration by typing the following: cd /Library/Preferences/SystemConfiguration
3. Edited com.apple.Boot.plist using vi under sudo (because the file is owned by root):
   1. sudo vi com.apple.Boot.plist
   2. Moved the insertion point down to the <string> associated with the Kernel Flags <key>
   3. Hit the "i" key to begin inserting text
   4. Typed darkwake=0
   5. Hit the "esc" key to exit insertion mode
   6. Typed ":wq" to save the file and exit
4. Rebooted the system.

Various Remote Desktop and VNC programs for the Mac act as a Remote Desktop Server, are likely to have their own WakeOnLan type settings. Less obtrusive than editing system files, it might be an alternative which works for you. After all, if a software is supposed to be able to remote in to a machine, it will have to wake it as well.

Brody, you already admitted that you have no idea what WoL is, so why are you even here hypothesizing about what may or may not be?

The issue that the OP stated has to do with the kernel's response to a WoL packet. The OP wants the original response, not the new, low-power wake response. Therefore, the kernel needs to be told not to do the Dark Wake thing. This requires editing a system file.

I'm just suggesting a possible work around. If the point is to wake up the computer to do remote access of some sort, getting remote access software that can do it, might be better. Why else would you want a Wake On Lan setting?

Let's talk about this in terms of people, rather than computers -- the ideas are similar.

If a person is sleeping, then they can be woken up easily because, subconsciously, their mind is still processing input from their environment. Therefore, if someone pokes them, their brain responds by waking up their conscious mind so that they can deal with whatever woke them up using their full, conscious mind and personality. This is similar to a computer that's sleeping and which responds to Wake on Lan packets in the classic fashion: their network card recieves the packet, realizes that it's a WoL packet, and sends a signal that powers up the CPU. The kernel (the core of the OS) running on that CPU then brings the whole system out of sleep so that it's ready to deal with whatever woke it up.

Different from this is the person who's been hypnotized. This person, much like your sleeping 10.7 system, won't respond to poking or other such stimuli by waking up fully. Some interaction is possible with this person, but only very particular input (such as someone clapping, or the ringing of a bell) will bring that person out of that hypnotized, low-power state. That person's mind knows what that input is, and when they recieve it, then they will wake up fully.

Dark Wake makes your computer act as if it has been hypnotized. Only certain input (requests for certain Bonjour services, in this case) will bring it out of the low-power wake state, and the kernel knows what that input is, just like the hypnotized person knows what cue will bring them out of the hypnotized state.

Can you see why what you suggest doesn't apply to this query? What you're suggesting is similar to dancing a jig next to a hypnotized person who's been told that they'll only wake up when they hear a particular gong. You can use remote access software all you want, but until that machine recieves a WoL packet followed by a request for a Bonjour service that the computer is offering, it won't come out of the low-power wake state, because that's the cue that it's been told to wait for. What you need to do is tell the computer (the kernel) that it should wake up fully as soon as it recieves the WoL packet and not wait for additional requests. And, so, we have to talk to the kernel by way of the boot configuration.

Thanks Quelqu Un for your support.

Very helpful.

- Peter -

Impressive help, thanks! 🙂

I like your solution of modifying the com.apple.Boot.plist file to disable darkwake. I decided to pursue an alternate solution though, since the Macbook I'm trying to wake belongs to a customer and I didn't want to modify it's sleep behavior.

I was trying to wake a Macbook Pro to have a Retrospect Backup Client on that Macbook respond to the Retrospect Pro software running on a WinXP PC. I noticed that even though the Macbook would respond to ping from the XP machine, Retrospect Pro reported no response from the Retrospect Client on the Macbook. The post from Quelqu Un explains the situation well. I was not aware of the darkwake mode.

I've been using a batch file to wake the other PC clients on the network using wolcmd (from depicus.com - great source of info on WOL). The batch file tests for ping response from the desired PC and if there's no response sends a WOL magic packet to that PC. I noticed that after modifying the batch file to wake the macbook pro that the ping response was good so the WOL magic packet was never sent. Even after defeating the test for ping response the magic packet was not waking the Macbook Pro to a state that allowed response from the Retrospect Client.

Since the WOL magic packet needs to be followed by a request for a serivce running on the Mac (thanks Quelqu Un!), I tried using telnet to send a request to the IP address of the Macbook Pro on port 5900 (VNC), since I had remote mangement & vnc enabled. This seems to work, since the batch file now wakes the Macbook sufficiently for the Retrospect Client to respond and the backup proceeds.

On a windows PC the batch file is as follows. I'm sure it could be implemented from OS X as well, but I'm not as familiar with scripting in OS X. Anybody want to provide the OS X (unix) equivalent?

wolcmd 406c8f1b5fa4 192.168.35.233 255.255.255.0 7

start telnet -a 192.168.35.233 5900

sleep 45

\SysinternalsSuite\pslist telnet

if %errorlevel%==1 goto NO_TELNET

\SysinternalsSuite\pskill telnet

Notes:

A) wolcmd parameters are: MAC addr, IP addr., SNM, port (see depicus.com for more complete explanation)

B) start telnet opens telnet in a separate window so the batch file can continue

C) sleep.exe (available in the Windows Server 2003 Resource Kit) - pauses 45 seconds

D) pslist (from Sysinternals.com) tests for active telnet process

E) pskill (also from Sysinternals.com) kills the telnet process, which hangs forever if not killed

That's the core of my batch file. Be glad to submit the rest if anybody's interested. Gotta run...