Screensharing App and Wake On Lan

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Level 1

5 points

Screensharing App and Wake On Lan

Hi everyone,

I´m having a question regarding Apple´s screensharing function. I´m using a late 2008 MacMini with El Capitan at home in my office. The Mini is wired via LAN to my local network. A late 2008 MacBook is used also with El Capitan in the same network most of the time via WIFI connection. Generally I´m able to use the MacBook to remote control the Mini in my office by Apple´s screensharing App. The problem comes when the Mini goes to sleep mode. If the Mini is in sleeping mode I´m not able to use the screensharing App to wake it up. Yes I controlled all remote access configs, so "Wake up by network connections" is turned on and I already switched that option with restarts and so on...nothing changed. The interesting thing is, that when I use a second party WOL app on my MacBook I´m able to wake the Mini, it wakes up in an instant. So my conclusion so far is, that there is something wrong with Apple´s Screensharing app, as it looks like, the app is basically working, but not able to send a WOL package to the sleeping Mac. Is anyone facing the same "problem" with the Screensharing app? Or did I miss anything in configurations?

I´m absolutely sure that in former times (Mavericks or even before) the Screensharing app was also capable of waking up my Mini as I used it a lot.

Thanks in advance for any help. 🙂

MacBook, OS X El Capitan (10.11.3), null

Posted on Feb 18, 2016 12:26 AM

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Answer 1

Top-ranking reply

John Lockwood

Level 6

13,697 points

Feb 18, 2016 8:11 AM in response to Forti-4T

Having done a bit more reading I am getting the impression that Wake-On-LAN and Wake-On-Demand are different things. Apple support WOL as shown in Energy Saver settings and as you found a WOL client can wake your Mac mini running El Capitan. However I get the impression ScreenSharing only uses WOD not WOL and hence possibly your problem and why it works for me. This being because my AirPort Extreme is acting as a Bonjour Sleep Proxy server for WOD.

WOD is a higher level system than WOL and I believe WOD utilises WOL at the lower levels.

While this is as the name Bonjour Sleep Proxy server suggests part of Apple's Bonjour that is merely Apple's name for their implementation of mDNSResponder aka. ZeroConf. As mDNSResponder is open source anyone could in theory port it to something else. See http://www.opensource.apple.com/source/mDNSResponder/

So far I have not found any complete implementations i.e. including the Bonjour Sleep Proxy server either for Linux or included in a non-Apple router. There are some but lacking the Bonjour Sleep Proxy Server function. 😟

Note: I believe any model of AppleTV can act as a Bonjour Sleep Proxy. Perhaps getting a cheap secondhand ATV2 or ATV3 is an option, also apparently even the AirPort Express can do this.

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Answer 2

Feb 18, 2016 5:05 AM in response to Forti-4T

I have several machines and laptops with different OS X versions but the one I use most often for ScreenSharing is running Snow Leopard.

I have just remembered something else. I also have an AppleTV3 on my network and both the AirPort Extreme and the AppleTV as supposed to act as proxies for Wake on Demand. See About Wake on Demand and Bonjour Sleep Proxy - Apple Support

You can use the following command to search for sleep proxy servers on your network.

dns-sd -B _sleep-proxy._udp local

(Do Control-C to stop it.)

In my home network it lists my two AirPort Extreme base-stations but does not list my AppleTV3. However the above article says that is correct if you have an AirPort Extreme on your network.

So the conclusion may be that in my case my AirPort Extreme is solving the issue.

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Answer 3

Feb 18, 2016 7:14 AM in response to Forti-4T

FWIW I tried this with a MBP and an iMac, both on El Capitan, and it worked fine - actually, it worked great. When the iMac was asleep, screen sharing woke it up; and when I quit the screen sharing connection it went right back to sleep. The only obvious difference in my case was that both machines were on the same wired network. Maybe this is related to the bridging from wireless to wired.

I did also try the same with the MBP connecting wirelessly. It was also able to wake the iMac up and share its screen, but this time on closing the connection the iMac did NOT go to sleep again automatically.

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Answer 4

Feb 18, 2016 3:35 AM in response to Forti-4T

I have a Mac Pro running El Capitan on Ethernet and a MacBook on WiFi. I can wake the Mac Pro using ScreenSharing although my MacBook is not using El Capitan.

I am however using an AirPort Extreme configured in bridging mode, is your WiFi 'bridged' to the Ethernet or is it routed and/or NATed?

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Answer 5

Forti-4T Author

Level 1

5 points

Feb 18, 2016 3:55 AM in response to John Lockwood

Hi John,

thanks for your help. I´m using a common german router (AVM Fritzbox 7390) for my home network, so there is no Apple Airport involved. As I can send the WOL package to the Mini via second party apps I´m pretty sure it must have to do something with sending that package from the MB when trying to connect with the screensharing app. I was running that scenario successfully on the same infrastructure just with an older Mac OS version some time ago......

If there is a bug in El Capitan in that way, it would explain, why you can wake up your PRO from your MacBook (which is not on EC yet) and I can´t...... Can you tell me what´s on your MacBook? Yosemite, Mavericks, Mountain Lion....? By that information I can quickly setup an old HDD with that system simply to check out if Mavericks or ML is working..... I´m quite sure that "bug" came with a system update because some updates ago it perfectly worked and I did´t change structures....

Thanks again

Sven

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Answer 6

Forti-4T Author

Level 1

5 points

Feb 18, 2016 7:01 AM in response to John Lockwood

I tried to search for sleep proxy servers but none showed up....what is OK as there are no ATV or Airports inside my network. But I can remember I once used an ATV1 & 2 in my home network...... Maybe the waking up problem occurred after deactivating the ATVs..... This could also be another explanation. I´m going to setup a Snow Leopard system on an external USB HDD and test if that solves the problem (which means its a OS bug) or if I can solve it by using an airport express....

Thanks so far

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Answer 7

Forti-4T Author

Level 1

5 points

Feb 18, 2016 7:24 AM in response to Luis Sequeira1

Hi Luis,

thanks for your trial....that´s exactly how it worked for me, when it was working. Do you have any Apple network infrastructure in your network, eg. Airports or ATVs? As John pointed out, this might help to transfer the "WOL package" to the sleeping mac. In my network is no further Apple equipment like that, maybe that´s the problem. So when you say that screensharing works fine for you I expect some Apple network equipment in your network?

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Answer 8

Feb 18, 2016 7:31 AM in response to Forti-4T

Forti-4T wrote:

Hi Luis,

thanks for your trial....that´s exactly how it worked for me, when it was working. Do you have any Apple network infrastructure in your network, eg. Airports or ATVs? As John pointed out, this might help to transfer the "WOL package" to the sleeping mac. In my network is no further Apple equipment like that, maybe that´s the problem. So when you say that screensharing works fine for you I expect some Apple network equipment in your network?

Actually, no.

I did this at my workplace and there was no Apple network infrastructure at all.

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Answer 9

Forti-4T Author

Level 1

5 points

Feb 18, 2016 8:02 AM in response to Luis Sequeira1

Nooooo..... I mean OK good for you but that´s not good for finding an explanation.... 😟

Although that´s exactly the way I would expect an Apple App like screensharing to work.....

So there´s nothing else than activating screensharing and setting the option waking up for network connections when you tried it?

OK....that´s what I did without being able to wake the Mini, neither when I tried it via WIFI or completely by wired LAN... 😟

But thank you anyway....

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Answer 10

Forti-4T Author

Level 1

5 points

Feb 18, 2016 8:41 AM in response to John Lockwood

I think I´ll give it a try as you said....taking a used ATV and checking out what happens when that is in my network. Although Luis has no further Apple equipment in his network and it is still working..... Curious thing....or his router is supporting Bonjour the way it is needed....

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