Wake on demand / wireless doesn't work anymore after a few hours

Discussion in 'iMac' started by generator, Jan 17, 2012.

  1. generator, Jan 17, 2012
    Last edited: Jan 17, 2012

    generator macrumors newbie

    Sep 23, 2009
    I use wake on demand regularly for screen sharing and my new Apple TV 2 among other things. But I noticed that after a couple of hours my iMac doesn't wake up over wireless anymore for any service. Before that it works perfectly.

    Does anybody know what could be causing it? I've checked every corner of the Internet, but haven't found a solution yet.

    My iMac does support Wake on Wireless, and the check-box for enabling it is checked.

    I thought it might be caused by the fact that I've extended my Airport Extreme with two Airport Expresses. But when I make sure that my iMac and my Apple TV are both connected to the Airport Extreme, it's still not working.

    I think my iMac should be waking every now and then to let my Airport Extreme know it's there. Is there any way I could check if this is actually happening withouth having to sit next to it for a few hours?

    Some extra information about my equipment:
    iMac 24" (Mid 2007, OSX Lion 7.2)
    Airport Extreme (3th generation, v7.6)
  2. lexvo macrumors 65816

    Nov 11, 2009
    The Netherlands
  3. generator thread starter macrumors newbie

    Sep 23, 2009
    He seems to be having the same problem. Unfortunately your links haven't helped me fix it.

    I have been monitoring my Airport Extreme closely, and it shows my iMac connected during the entire day. It even wakes it at a set interval. But overnight it disappears from the list.
  4. lexvo macrumors 65816

    Nov 11, 2009
    The Netherlands
    OK, a year ago I was wrestling with the same problem. However, I didn't have an Airport Extreme at that time. Buying an Airport Extreme solved my problem. Obviously it doesn't solve your problem.

    I think it has something to do with the so-called Bonjour service. This service should automatically be setup.

    Here are two more technical sites describing this:


    I retrieved these sites from the links I saved from a year ago. I can remember it was a very though search and finding out why things didn't work.

    But like I said in my situation buying an Airport Extreme solved my problem. And it worked for you also before. Maybe this is a drastic measure, but have you tried a factory reset of your Airport Extreme? BTW, you have to configure your Extreme again after a factory reset.
  5. generator thread starter macrumors newbie

    Sep 23, 2009
    Thanks, for the links. But wake on demand is working, but only for a day or so. When I wake my computer manually it will work for a day again.

    I'm gonna try resetting the airport to factory defaults when I've got the time. It's just so annoying that there is no way to instantly see if it's working again, it could take several days.
  6. lexvo macrumors 65816

    Nov 11, 2009
    The Netherlands
    I just remembered I once had the same problem as you after I bought the Airport Extreme. I vaguely remember I did a PRAM and SMC reset on my iMac to solve the problem. I'm not 100% sure because this was months ago but maybe it is worth a try.

    From my own experience I know that solving problems like this is awkward.
  7. generator, Jan 19, 2012
    Last edited: Jan 19, 2012

    generator thread starter macrumors newbie

    Sep 23, 2009
    I've been monitoring my Airport Extreme (The graph at the "Wireless clients" section). I've noticed the following:

    - When my mac is listed there, I can wake up my mac. When it isn't I can't.
    - The graph shows my iMac waking up for a few minutes every hour or so during the day (like it should).
    - Sometimes (usually in the morning) my iMac isn't listed. But I noticed today that it comes back a couple of hours later. So it seems my Airport Extreme is experiencing some blackouts where it just completely forgets about my iMac.

    P.S: Thx for the tip lexvo, tried it. But I don't think it worked.
  8. marc.garcia macrumors regular

    Jul 26, 2010
    Hello generator,

    I would like to know if you ever got around to solving this. I've recently purchased a Mac mini and it feels like I maybe suffering from the same kind of thing. I am very interested in your opinion and experience because you seem to have analised multiple possible causes of the problem.


Share This Page