Wake on Lan works on my MacBook Pro, not on my iMac...

Question

Wake on Lan works on my MacBook Pro, not on my iMac...

Hello everyone, with all these threads about the problem, I wanted to start a new one to make it clear, with all information you may need in order to help me out.

I've got a MacBook Pro '15 and an iMac 21.5', both are running (clean install) OS X Mountain Lion 10.8.2, both are up to date with the latest updates, both have the same apps, both have the same settings in "system preferences", and of course the same settings in "sharing" options.

My iMac is connected to my 5GHz network from my Time Capsule while my MacBook Pro use the 2.4GHz network.

Before going to bed, I leave both my Macs turned on, after 10min they go to sleep automatically. In the morning I can wake up my MacBook Pro from my iPhone or iPad with a screen sharing app.

The iMac doesn't respond at all. It stays in sleep mode. I can leave my MacBook Pro asleep for a week, it always responds. The iMac responds after a few hours but after 6 or 8 hours it seems to be completely asleep and doesn't respond to anything. If you think it's about the iPhone/iPad's app, when I try to wake the iMac from my MacBook Pro with "Back to my Mac" I have the same results.

I tried to connect my iMac to the 2.4GHz network: same problem.

OF COURSE "WAKE ON LAN" is activated in my system preferences.

I made a reset of the PRAM, the cache and the SMC on my iMac: same problem.

I type sudo periodic daily weekly monthly in the terminal and sudo dscacheutil -flushcache: same problem.

I tried everything I may have found in the forums or on this Support from people having the same issue: same problem.

I even tried to set the iMac with the same sleep mode as my MacBook Pro: same problem.

PLEASE HELP ME!

iMac (21.5-inch Mid 2011)

Posted on Dec 2, 2012 3:24 AM

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Answer 1

Eric Root

Level 10

685,257 points

Dec 2, 2012 1:37 PM in response to loïcfernandezcastrillon

Have you submitted feedback to apple?

http://www.apple.com/feedback/

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Answer 2

Dec 2, 2012 1:57 PM in response to Eric Root

Yes I already sent it.

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Answer 3

Dec 21, 2012 3:03 PM in response to Eric Root

Do you think pmset -g networkoversleep 1

Can solve the issue? By default it's ser to 0.

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Answer 4

John Galt

Level 10

155,804 points

Dec 21, 2012 3:17 PM in response to loïcfernandezcastrillon

loïcfernandezcastrillon wrote:

Do you think pmset -g networkoversleep 1

Can solve the issue? By default it's ser to 0.

Mine is set to 0 and it wakes. 5 GHz, 2.4 GHz, Ethernet, makes no difference.

Have you tried resetting your Time Capsule? Perform a "hard reset" and reconfigure it. Perhaps for some inexplicable reason it is not sending your iMac the "magic packet" required for Wake on LAN.

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Answer 5

Dec 21, 2012 3:20 PM in response to John Galt

Yes I tried to reset Time Capsule, AirPort Express, even my router...

I made a clean install of OS X 10.8.2 and the problem is still here :(

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Answer 6

John Galt

Level 10

155,804 points

Dec 21, 2012 4:03 PM in response to loïcfernandezcastrillon

loïcfernandezcastrillon wrote:

Yes I tried to reset Time Capsule, AirPort Express, even my router...

I thought the Time Capsule was your router:

... My iMac is connected to my 5GHz network from my Time Capsule while my MacBook Pro use the 2.4GHz network.

Big difference. Your router is responsible for issuing the "wake on LAN" packet. If it's not a genuine Apple router it may not work.

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Answer 7

Dec 22, 2012 12:05 AM in response to John Galt

I'm connected with the WiFi of my Time Capsule (bridge mode). I have this configuration since Snow Leopard, and no troubles...

The problem came with OS X Lion 10.7.2 or 10.7.3 I can't remember and also with the AirPort update 7.1, there was a WiFi update for the iMac. Those updates came quite at the same time.

I'm not the only one with this issue, iMac, MacBook Pro, Mac mini, Mac Pro... Everyone as trouble, using Time Capsule, AirPort Extreme as router or bridge.

https://discussions.apple.com/thread/3730063?start=0&tstart=0

There are tons of threads like this one.

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Answer 8

Dec 22, 2012 12:27 AM in response to loïcfernandezcastrillon

I've set networkoversleep to 1, I'll leave the iMac in sleep 8 hours and see...

The Wake on Lan from Time Capsule works well, it's the iMac the problem, when asleep if I check AirPort utility from another Mac or iPhone/iPad, I can see the devices connected. The iMac stays connected to the Time Capsule about 6 hours during sleep. Then it dissapears...

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Answer 9

John Galt

Level 10

155,804 points

Dec 22, 2012 8:24 AM in response to loïcfernandezcastrillon

loïcfernandezcastrillon wrote:

I'm connected with the WiFi of my Time Capsule (bridge mode). I have this configuration since Snow Leopard, and no troubles...

I understand that, but if your router is not an Apple AirPort Base Station then it introduces an element of uncertainty. Apple has implemented many changes related to wireless networking recently.

You are complicating matters by changing networkoversleep:

networkoversleep - this setting affects how OS X networking presents shared network services during system sleep. This setting is not used by all platforms; changing its value is unsupported.

Solving problems like this requires that you simplify your network environment and eliminate its unknowns. Using third party routers and making unsupported changes runs counter to simplification.

The iMac stays connected to the Time Capsule about 6 hours during sleep. Then it dissapears...

The iMac wakes periodically (every few hours) to inform your router of its network presence for Wake on LAN demands. Try changing your router's DHCP lease period to something longer than a few hours. For a home environment, a few days is more appropriate. This may not solve the problem, but it is better than making unsupported changes to your system.

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Answer 10

Dec 22, 2012 8:21 AM in response to John Galt

The problem is that my router don't have bridge mode, and if I choose to use Time Capsule as router it says that both have DHCP, and it does not work.

But this afternoon I may have found something:

While trying a lot of things to solve the issue, what I did was to reset the Time Capsule, then from my iMac I set it up using AirPort Utility.

Usually I connect to my 5GHz network. By setting up the Time Capsule from my iMac, it has now in Keychain the passwords for the 2.4 and the 5GHz. And in Network Preferences/prefered networks I've the 5GHz at the top (because I want to use it) and 2.4 below.

Now is the strange part, when I leave my iMac asleep for a while it disconnects from the Time Capsule to connect to my AirPort Express. I noticed that while using AirPort Utility from my MacBook Pro. My Time Capsule spreads 5 and 2.4GHz and the Express only 2.4GHz. My iMac is not in the same room as Time Capsule.

So here is my conclusion, after a few hours of sleeping, the iMac enters in a deeper sleep, and the WiFi signal is maybe very low. Before it was disconnecting from Time Capsule, because the distance was too long. Now it connects to my AirPort Express next to it because it has the passwords to log to it.

I'll let it during the night, see if tomorrow it will be still connected.

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