ATV 3 Home Sharing/Wake on LAN problem

Discussion in 'Apple TV and Home Theater' started by GarrettL1979, Apr 24, 2012.

  1. GarrettL1979 macrumors 6502

    Feb 15, 2012
    The past two mornings I have tried to access my iTunes library on my sleeping MBP (lid open) through home sharing. I have "wake for network access" enabled, and the ATV definitely recognizes that the library is there, but it won't connect. I tried using the remote on my iPhone but had the same problem-- I tap the fully lit iTunes Library icon, but the connection never occurs. Home sharing normally works really well. I seem to only have problems when the computer has been asleep for an extended period of time.

    My MBP is connected w/ethernet, running 10.7.3, and I'm using a new AEBS.

    Any suggestions for fixing this?
  2. EmpyreanUK macrumors regular

    Mar 6, 2011
    This is a known issue, and has been affecting me personally for the whole time I've been using Lion. Nobody has any definitive solutions, but there is another thread on the topic (which you have posted in) which has a few possibilities.

    I personally suspect that the issues people are having with this are a compound of at least two separate bugs, one relating to the so-called 'dark wake' (low-power wake) feature, and another relating to Bonjour sleep proxy registrations. Who knows if and when they'll be identified and fixed, though. Judging from recent news stories on this website, it seems as though 10.7.4 should soon be released, so perhaps we will have some luck with that (though I'm not holding my breath).
  3. GarrettL1979, Apr 25, 2012
    Last edited: Apr 25, 2012

    GarrettL1979 thread starter macrumors 6502

    Feb 15, 2012
    Thanks! I tried the dark wake = 0 setting last night, but to no avail. Maybe I need to restart my computer in order for the changes to take effect? What's so strange is that my ATV is definitely aware that my iTunes library is there-- the movie images from my iTunes library are available on top of the computer menu option-- it just won't connect. It's almost like home sharing times out after an extended period of sleep.
  4. EmpyreanUK macrumors regular

    Mar 6, 2011
    I would definitely try resetting your computer to see if that makes the changes take effect.

    Your problem sounds similar to the one I'm having. From the poking around I've done, I think this is because the Mac registers itself with a device capable of acting as a Bonjour Sleep Proxy (this could be an Apple networking device, or even an ATV2/3) as being available for wake-on-network access. The Bonjour Sleep Proxy then advertises this Mac's services (iTunes Home Sharing being one of them) on its behalf. Your ATV library, other machines running iTunes and iOS devices see the sleeping Mac's library being broadcast as available. They do not know it is on a sleeping Mac, but just see it as available. They attempt to access the library, and in doing so contact the Sleep Proxy with a request effectively saying 'I want to access this iTunes library'.

    The sleep proxy, however, knows that the Mac is asleep. It then broadcasts the so-called 'magic packet', which is a piece of information sent out over the network, and which a sleeping Mac (with wake-on-network turned on) is listening for. In theory, the Mac should 'hear' this piece of information, interpret it as an instruction to wake up, and then wake up and take over it's Bonjour services, in this example serving up the media content over iTunes Home Sharing.

    What I think is happening, in the case where the library is seen as available by client devices but nonetheless inaccessible, is that the sleeping Mac is either not receiving or not responding to the magic packet. The Sleep Proxy is still broadcasting the iTunes library as available, on behalf of the sleeping Mac, but is unable to wake it up.

    Another widely reported problem, one which I am also experiencing, is that whereby the library is not listed at all. A Mac running wake-for-network is supposed to periodically awaken to renew its registrations with the Bonjour Sleep Proxy. This isn't happening, and so the Sleep Proxy doesn't even consider the Mac as available, and hence the iTunes library is not listed as available (or even existent) to other devices on the network.

    I suspect that both of these problems are a symptom of the same underlying bug. Once my Mac goes to sleep, it does not properly listen for wake-up requests and nor does it maintain its sleep proxy registrations; it would seem as though sleeping my Mac also switches off the low-level networking functionality required to perform each of these tasks. It's as though I want it to enter sleep, but it is instead entering a coma. Only manual intervention (me wiggling the mouse) is able to wake it up.

    The strangest thing of all is that it isn't a consistent problem. Whilst most of the time, wake-for-network does not work, it occasionally (and seemingly randomly) does. When I'm at work, for example, and using my Macbook, my iMac at home will sporadically appear as available over Back to my Mac (which depends upon properly functioning sleep proxy registrations). When this happens and I try to access it, I'd say that about half of the time the Mac actually wakes up and allows me to connect to it.

    Bizarre and frustrating.
  5. GarrettL1979 thread starter macrumors 6502

    Feb 15, 2012
    Interesting. I tried restarting, but no luck. Are there any bonjour changes I can make to fix this? I'm guessing no...

    My library used to not show up at all when I was using an older Linksys router. I recently purchased an AEBS, and I can now at least see the library. Of course, it still doesn't connect. I even tried waking the computer up by tapping a few buttons-- which works and the computer wakes-- but home sharing will still not connect. I have to actually close the lid and reopen it after a few minutes, or turn home sharing off/on. So strange.
  6. borisp, May 15, 2012
    Last edited: May 15, 2012

    borisp macrumors newbie

    Jan 5, 2005
    I had the same issues. Once the mac with iTunes running woke up on LAN it seems ATV and other iTunes clients were not able to get the remote iTunes library. I wrote a little app that runs on my mac running iTunes. The app will get a notification if the mac returns from sleep and pokes iTunes a bit. Worked for me but I've not tested it in the wild. Download:
  7. GarrettL1979 thread starter macrumors 6502

    Feb 15, 2012
    thanks! i'll give it a shot

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