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Waking up a computer over a network

Discussion in 'Mac OS X Server, Xserve, and Networking' started by thomasp, Jun 23, 2008.

  1. macrumors 6502a

    If one Mac (Mac "A") is asleep on a small wireless network and another (Mac "B") wishes to access its hard drive via file sharing, how can Mac B wake up Mac A remotely? Both macs are running Tiger.

    I've noticed there's something in the energy saver system prefs that allows you to "Wake for ethernet network administrator access" - is this what I want?

    Thanks for the help :)
  2. Moderator


    Staff Member

    Yes. Ensure that checkbox is checked. You then need to sent it a WOL (Wake-On-LAN) packet. You can send a WOL packet with this software. Note that file sharing will not send a WOL packet on it's own.
  3. macrumors 68000


    might be stating the obvious but the sleeping needs to be on a physical ethernet connection, doesn't work over Wi-Fi. :)
  4. macrumors 6502a

    Thanks - need to test it more thoroughly but it seemed to work.

    Are you sure? It worked when I tested it and the computer was connected as follows:

    Powerbook --> Wifi --> Router --> Wireless bridge --> Ethernet cable into iBook

    I should have been clearer earlier - it's not a straight computer-to-computer wireless connection, it's going through a router.
  5. macrumors G5


    Unless you assign your computer a static address on your network and have the setting passed through the wireless access point, all wireless routers typically refreshes the wireless IP periodically (usually 1 week), when that happens, if you have multiple wireless clients, the IP assignment is likely to change. If the IP changed then you can't connect.
  6. macrumors 6502a

    The software linked above seems to work on MAC addresses, not IP addresses, and since they're surely fixed with the computer's hardware, they won't change when the router renews the IP addresses.
  7. Moderator


    Staff Member

    As long as the sleeping computer is on a wired connection it'll work. The non-sleeping computer can be on WiFi.
  8. macrumors 6502a

    When you say "Wired" do you mean connected to the ethernet socket, because the iBook in my example above is technically on a wireless connection, it just lacks a wireless ethernet card.
  9. Moderator


    Staff Member

    Yes I mean connected to the network via an ethernet socket. And technically it's not on a wireless connection: it's using it's ethernet port so is wired to another network device.

    The reason that it has to be on an ethernet port is that the Mac won't keep the WiFi connection open (power issues) when sleeping. In this case the bridge will still be powered as it's an independent device...
  10. macrumors 6502a

    Ah right, thanks for that. So does the same go for wireless PCI cards installed in a G4 tower? If so, I'll have to abandon that route and upgrade the wireless bridge instead.
  11. Moderator


    Staff Member

    I would imagine so, unless the card documentation specifically states otherwise.

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