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I am researching the best way to wake my computer through a firewall over the internet remotely (the computer to be woken is a Mac). Through external research, I have seen that I should be able to send a "Magic Packet" with the MAC address of the computer to be woken to UDP port 9, and that should wake the computer (I will turn on Ethernet Management under the Energy folder in System Preferences as well as port forwarding for port 9 in the firewall).

  1. I was wondering if there is a way to edit an Access Control List or some other file on the Mac so that only packets coming from my specific external IP address on port 9 are honored (i.e., to prevent an external attacker from constantly waking up my computer).

  2. I was also wondering if there is a convenient command line utility for sending magic packets over the internet with a Mac (rather than over LAN).

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migrated from serverfault.com Jun 24 '13 at 10:13

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1 Answer 1

Magic packets are not generally routable over the Internet, because

  • they are sent as broadcast frames, so the destination MAC address must be the broadcast address (ff:ff:ff:ff:ff:ff), and
  • even if they weren't, your computer will be asleep at the time, so the local router won't get a response to an ARP request for your computer's IP address.

You can wake up your computer remotely, but you need to do it with

  • directed broadcasts (you'll need your local router to generate a broadcast frame when it routes a packet into your local network with a broadcast IP address), or
  • some local device that will generate the packet for you. Some domestic routers can do this natively.
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