Wake On LAN (WOL) on Mac Mini?

Discussion in 'Apple' started by David Arnstein, Dec 16, 2007.

  1. I cannot make WOL function on my new Mac Mini. I am using the wired
    ethernet interface. I enabled System Preferences / Energy Saver / Options
    / "Wake for Ethernet network administrator access."

    I used the old reliable perl script wakeonlan to send "magic packets"
    to the Mac Mini. Lots of magic packets. The Mini kept sleeping. Moving
    the mouse wakes it up immediately, so I know that it is not dead.

    Is there anything else I can try?
    David Arnstein, Dec 16, 2007
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  2. Mouse movement should only "wake" the display, not the Mac. If your
    mini's pilot light isn't throbbing, it's not really sleeping.
    Neill Massello, Dec 16, 2007
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  3. David Arnstein

    David Empson Guest

    I have a current model Mac Mini connected via Ethernet and I'm able to
    wake it using the freeware WakeOnLAN application (and its widget), so
    the feature definitely works.
    How immedidately? If it instantly turns on the screen without making any
    noises, then it wasn't asleep - it has just dimmed the screen.

    Was the white LED on the front pulsing? That shows it is on but asleep.

    My Mini recalibrates the optical drive and takes a couple of seconds to
    wake up.
    David Empson, Dec 16, 2007
  4. I think that there is a quirk in the Mac's WOL behavior. I find that
    if Airport (WiFi) power is ON, then WOL will not work. If I turn
    Airport off, then I can wake up my Mac Mini from another computer on
    my wired LAN.

    Is this the expected behavior? It seems a bit strange to me. I mean, I
    am always using the wired ethernet port on my Mac Mini. That is where
    the WOL magic packet enters. Why should the Mini "care" that the
    Airport radio is also powered up?
    David Arnstein, Dec 18, 2007
  5. David Arnstein

    David Empson Guest

    Recognition of the magic packet is a feature of the Ethernet controller
    and this feature isn't supported by Airport. It operates by leaving part
    of the Ethernet controller powered on while the rest of the computer is
    asleep. If the Ethernet controller receives the magic packet, it sends a
    signal to the power management system to wake up the rest of the

    The magic packet has to contain the MAC address of the Ethernet
    controller for the computer to be woken up (and it contains additional
    copies of the MAC address in the body in a special format).

    There is no concept of "looking for" a magic packet on an Airport
    network. If one happens to be sent via Airport, it will be received and
    discarded if the target computer is awake and do nothing if the target
    computer is asleep.

    If Wake On LAN isn't working with the Airport powered on for David
    Arnstein's Mini, the problem might be related to the order of the
    network interfaces in the network configuration.

    There could be confusing results if the Airport is connected to the same
    LAN as the Ethernet port, as other computers might be sending a magic
    packet with the wrong MAC address (using the MAC address of the Mini's
    Airport interface rather than its Ethernet interface).

    I should be able to test this one with my own Mini (later).
    David Empson, Dec 20, 2007
  6. David Arnstein

    David Empson Guest

    I've now tried it and can't fault it. I can use Wake On LAN to wake up
    my Mini (addressed to its Ethernet MAC address) whether or not its
    Airport is enabled.

    I only tried it with the Airport network connected to the same LAN. I
    haven't tried forcing it off the wireless network so Airport is active
    but unconnected.

    This is a current model Mac Mini.
    David Empson, Dec 20, 2007
  7. Where does Bluetooth come in this? Is waking via that a possibility?
    Hylton Boothroyd, Dec 21, 2007
  8. David Arnstein

    David Empson Guest

    Bluetooth has a mechanism to wake the computer, as does USB.

    I'm less familiar with the specifics, but I expect it requires the
    Bluetooth and/or USB controllers to remain at least partially active
    while rest of the computer is asleep, and it will require some power
    being supplied via USB.

    For a USB keyboard to wake the computer, it must be getting enough power
    from the keyboard to be able to register a keystroke and send a message
    to the computer.

    Bluetooth is somewhat easier, because the peripherals are battery
    powered. The computer only needs to be passively listening, and any
    activity message from the device will wake up the computer.

    Inside the computer, I expect there is a signal from the Bluetooth or
    USB controller to the power management system, as with the Ethernet
    controller. This signal will be activated to wake up the computer (if it
    isn't already awake).
    David Empson, Dec 21, 2007
  9. Thank you. That was the key remark I needed.

    Although I don't understand the implications of all the things I've
    click-selected on their Bluetooth panels, your advice was enough to keep
    me persisting until I'd used Bluetooth to successfully waken my wife's
    PowerBook on Panther from my Intel MacMini on Tiger.

    There's a lot more for me to get my head round, not least what to do to
    stop it going back to sleep around 20 seconds later!

    I've already been using the Bluetooth connection for a couple of months
    (I think -- they've both got WiFi) to print on the PowerBook's USB
    printer. For that it's enough for the PowerBook to be awake -- it
    doesn't need anyone to have been logged in through the keyboard.

    So I've been able to go to the sleeping PowerBook
    - press Escape
    - wait for the password request to come up
    - ignore it, but press Escape
    and then the PowerBook would stay awake for its normal-wait-until-sleep
    period while I sent printing through to its USB printer (that is, for
    around 90 minutes)

    Now I need to find what to do to get an equivalent effect via Bluetooth
    that likewise allows the innards stay awake for 90 minutes.
    Hylton Boothroyd, Dec 21, 2007
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