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Waking Mac from sleep problem

Message #1 - Posted 2005/01/19 - Donald H. Gudehus

Hello all,

In Mac OS 10.3.7 one can enable "wake on ethernet network administrator access" in the system preferences. To wake up the Mac one then can send from another machine on the local area network, the "magic packets", i.e., 6 Hex "FF" followed by 16 repetitions of the hardware address of the ethernet card (MAC address) to port 9 on the Macintosh. There are several free programs on the internet which can allegedly do this, e.g., wol at http://www.gcd.org/sengoku/docs/wol.c, http://hp.vector.co.jp/authors/VA000770/docs/wol.c, and http://darmstadt.homeip.net/~gast/. There is also a python script at http://www2.cs.lth.se/X-tips.html#Vack_datorn_over_natet and http://www.majid.info/mylos/weblog/2002/05/20-1.html. I have tried these programs from a Linux machine on my LAN. In each case the Macintosh doesn't wake up. If I look at the arriving packets on the Macintosh with tcpdump, I see a possible reason for the failure, "udp port discard unreachable". Port 9 is called the discard port. On the Macintosh, I have tried both turning off the firewall, and turning on the firewall with port 9 enabled, but to no avail. I also tried enabling Remote Desktop Access under Sharing. Does anyone have any experience with waking the Mac from its sleep state? All help much appreciated!

Donald Gudehus

Message #2 - Posted 2005/01/20 - Kevin McMurtrie

Previously, Donald H. Gudehus wrote:

Hello all,

In Mac OS 10.3.7 one can enable "wake on ethernet network administrator access" in the system preferences. To wake up the Mac one then can send from another machine on the local area network, the "magic packets", i.e., 6 Hex "FF" followed by 16 repetitions of the hardware address of the ethernet card (MAC address) to port 9 on the Macintosh. There are several free programs on the internet which can allegedly do this, e.g., wol at http://www.gcd.org/sengoku/docs/wol.c, http://hp.vector.co.jp/authors/VA000770/docs/wol.c, and http://darmstadt.homeip.net/~gast/. There is also a python script at http://www2.cs.lth.se/X-tips.html#Vack_datorn_over_natet and http://www.majid.info/mylos/weblog/2002/05/20-1.html. I have tried these programs from a Linux machine on my LAN. In each case the Macintosh doesn't wake up. If I look at the arriving packets on the Macintosh with tcpdump, I see a possible reason for the failure, "udp port discard unreachable". Port 9 is called the discard port. On the Macintosh, I have tried both turning off the firewall, and turning on the firewall with port 9 enabled, but to no avail. I also tried enabling Remote Desktop Access under Sharing. Does anyone have any experience with waking the Mac from its sleep state? All help much appreciated!

Donald Gudehus

The wakeup happens at a low level in hardware so it doesn't matter what MacOS thinks of the packet. You might be having problems getting the wakeup packet routed to the Mac while it's sleeping. That's the big flaw in the wake-on-LAN protocol.

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