Filed under: Wireless, Snow Leopard
Snow Leopard extends Wake-on-LAN feature... if your config is right
It's been a stealth feature of modern Macs for years: the ability of a sleeping machine to respond to a 'magic packet' delivered over Ethernet and wake up on command, either triggered by a specialized app or by Apple Remote Desktop. Handy, especially for administrators who might need to access remote and sleeping workstations, but as the world has moved more toward wireless networking the Wake-On-LAN capability became gradually less relevant.Now, as Macworld explains, the ability to wake sleeping Macs remotely has been extended in two vital ways with Snow Leopard as a new feature called Wake on Demand. First, the new OS allows sleeping machines to hand off Bonjour broadcast tasks (advertising services like printer sharing, web sharing, iPhoto & iTunes libraries, etc.) to an Airport Extreme base station or Time Capsule, letting the machine's services appear always-on even if the actual Mac is asleep; the Mac will wake remotely when needed by a client. This alone will allow multi-Mac homes to sleep their machines more often, saving energy and aggravation.
The second feature requires that you pair your recent-vintage Airport with a recent Mac model (all 2009 versions, and possibly some 2008 models as well): you can wake the machine over Wi-Fi, rather than just over Ethernet. If you go to System Profiler, to the Network section and the Airport data sheet -- look for a line that says "Wake on Wireless." If it's there, you've got the capability. Your mileage may vary but it's certainly fun to try waking up your machine remotely over the WLAN -- or, for fun, your spouse's machine, just to watch them jump.
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Reader Comments (Page 1 of 2)
Murphy Mac said 3:27PM on 8-29-2009
I love wake on lan. I've got a Widget I use to wake up my G5 from my Macbook. http://www.readpixel.com/wakeonlan/
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willie said 1:00AM on 8-30-2009
You said all 2009 models, but my February '09 Unibody 15" MacBook Pro doesn’t have this line in the System Preferences: http://twitpic.com/fqlkn
This sounds like it would be pretty useful in combination with something that could send Wake on LAN packets over the internet, for screen sharing. If my router could forward that magic packet…
In short, does this work with my machine, and if so, does it require an AirPort or will another router with the right configuration do?
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Mo said 5:32PM on 8-30-2009
System Profiler, not System Preferences. The System Preferences bit is under “Energy Saver”.
John.B said 9:23PM on 8-30-2009
@Willie, that Mister-Smith screenshot is of Leopard, not Snow Leopard.
willie said 7:54PM on 9-01-2009
Yeah, I realized my mistake a little while after I posted, but I’ve been too busy since then to post about it.
Note to self: When brain is too fried to continue homework, it is also too fried to post comments on blogs.
samgross144 said 3:47PM on 8-29-2009
From the reports I've seen (and my own experience), Wake on Demand will work over LAN with most modern macs, and wake over wireless will work with any 2008 (or later) vintage mac that has built in WiFi (this excludes the early-2008 Mac Pro). The early 2008 MacBooks and Macbook Pros work fine.
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Glenn Fleishman said 3:55PM on 8-29-2009
Since I wrote the Macworld article, I keep testing and getting more reports about 2008 models; samgross144 is on target.
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cdogg said 4:03PM on 8-29-2009
After testing this on my 2009 iMac the fans went into full speed! Anyone else have this issue?
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Matt said 4:16PM on 8-29-2009
Looks like you can't access a notebook if it has been closed. It can be asleep, but the screen must be in the up position.
Anyone find different results?
(2008 MBP)
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Cycomachead said 5:34PM on 8-29-2009
This could very likely be a limitation. Have you tried it with the laptop plugged in? With it plugged in and to a display, keyboard, and mouse? I believe it is plugged in only because if you look at the Energy saver preferences for a laptop, it ONLY shows up under "Power Adapter"
The power management of laptops seems very odd sometimes, but it really is trying to make sure you don't break the laptop. Close laptop + screen on = lots of heat.
Also, the energy saver pane can tell you if you have the feature or not. My unsupported Macs say "Wake on Ethernet Network Access" whereas my new iMac says "Wake on network access"
lo_fye said 4:21PM on 8-29-2009
sounds designed to allow you to use your full-powered mac via remote desktop running on a thin tablet!
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NoAndThen said 4:39PM on 8-29-2009
I can't get my unibody macbook to keep broadcasting my itunes library. I have a Time Capsule... is there a setting I need to change?
This article makes it seem like it's automatic, but I've yet to see this be the case. Any help here folks?
Thanks!
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NoAndThen said 5:02PM on 8-29-2009
Ok, so I had to change the preference pane: Energy Saver-->power adapter-->"wake for network access."
It only works when plugged in. Makes sense, but is lame at the same time.
Also it definitely does not work when the lid is closed. You can put it to sleep and then close the lid and it will still broadcast, but unless you're right there to open the lid when it wakes it goes back to sleep and the remote client iTunes just hangs on loading the library.
Cycomachead said 5:37PM on 8-29-2009
Yes, this makes sense. The only supported way to let an Apple laptop work with the display closed is if it supports "Lid Closed Operation" which has a display, keyboard, and mouse connected. All Macs since the MacBook, as well as the PowerBooks support lid closed operation.
It's a safety precaution for the heat created by the display. There are apps to get around that, as well as magnets work sometimes.
NoAndThen said 11:08AM on 8-30-2009
@Cycomachead: I don't know what you're running, but my unibody MacBook can be running full tilt (150F+) encoding or whatever, and the screen is the coolest part of the whole notebook by far. The LED makes a huge difference. I want to see Apple build some heat piping into the screen to really make these unibodies the best the can be. The cooling potential is massive- if you could use the surface of your lid (solid aluminum and cool to begin with, never mind the most open air surface area) it would open up more powerful graphics in smaller spaces, as well as cut down energy usage significantly. I can dream..
Ben said 5:06PM on 8-29-2009
Is there a feature called Wake-When-I-Plug-In-A-MacBook-Even-Though-It's-Closed? Better yet, is there a way to turn that off? I'm trying to prevent a MBP from waking every time I want to charge the battery.
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TR said 8:20PM on 8-29-2009
So I’m not crazily alone. I thought my MacBook kept waking up when I plugged it in too...
Cycomachead said 5:39PM on 8-29-2009
No, but the mac goes back to sleep right away if the display is closed. Sometimes, my MacBook (2006) seems to go to sleep even if the display is open...
Benjamin said 6:32AM on 8-30-2009
I don’t know if there are any utilities that provide a graphical interface for it, but you can use Terminal to change the ‘acwake’ setting using the pmset command.
I think ‘sudo pmset -a acwake 0’ would do it. You’ll need to type in your account password for sudo. ‘pmset -g’ should verify that acwake has been changed to 0 afterwards.
Ben said 2:37PM on 9-01-2009
Thanks for the tip, benjamin, but it didn't work.