Mac – Wake MacBook on Wi-Fi without AirPort Extreme


I know that Snow Leopard brought us the option to magically wake our computers from far away if you had an AirPort Extreme base station, but has anyone found a way to do this with a standard or ISP provided router? What about using a bridge device to hook the MacBook up to Ethernet but from another room?

Best Answer

  • Macs that are capable of Wake on Wireless (WoW) and have it enabled will attempt to stay associated to the AP while asleep, and look for standard Wake on LAN magic packets. So any AP that will let the client stay associated and any solution that can deliver a standard Wake on LAN magic packet to the client should work.

    Unfortunately, modern Wi-Fi security mechanisms like WPA and WPA2 may want to roll the unicast keys sometimes and often roll the multicast/broadcast (group) key, and the sleeping Mac has no support for rolling keys while asleep. So if your AP disassociates the client because it's not responding to attempts to roll the keys, you won't be able to get a magic packet to the client. You could work around this by downgrading your security to static WEP or no wireless security, if wireless security is not important for your network.

    The AirPort Extreme provides three major services to sleeping Macs:

    1. It allows WoW-capable Macs to tell it that they're going to sleep, and it will defer key-rolling on those clients so that they can stay associated while asleep even under WPA and WPA2. As I mentioned, you might be able to work around this by downgrading your security.

    2. It provides Bonjour Sleep Proxy (BSP) service so that services advertised by the client stay advertised while the client is asleep, not just on the local network, but also via Wide Area Bonjour and Back To My Mac if those services are configured. It doesn't sound like this is a "must have" in your scenario.

    3. As part part of BSP service, if something tries to connect to one of the advertised services while proxied on the AP, the AP will send a Wake on LAN magic packet to the sleeping client to wake it automatically. You just need to find some other Wake on LAN magic packet sending tool, and some way to get it invoked "from far away" as you put it.

    Note, though, that BSP service is also provided by current (2nd-gen, small, black, $99) Apple TVs, as well as Time Capsules, AirPort Expresses, and as you mentioned, AirPort Extremes. So if you have, say, and Apple TV on your network, I believe it'll take care of #2 and #3 for you, so you just have to solve #1.

    Your suggestion of using a separate Ethernet-to-Wi-Fi bridge might be the easiest solution. If you keep the bridge on all the time, it'll stay associated to your Wi-Fi network, and now the MacBook only has to do normal wired Ethernet Wake on LAN, which is straightforward. You just have to pick a tool for sending magic packets.

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