Remote Power On - The Magic of Magic Packets

Have you ever wanted to turn on all of your boxes at the same time? I simply send one command and all of my other boxes turn on.

How?

I send out a magic packet.

From Wikipedia:

"The Magic Packet is a broadcast frame, transmitted over port 0 (Historically the most common port used), or 7 or 9 (becoming the most common ports used). It can be sent over a variety of connectionless protocols (UDP, IPX) but UDP is most commonly used. The data that is contained in a Magic Packet is the defined constant as represented in hexadecimal: FF FF FF FF FF FF followed by sixteen repetitions of the target computer's MAC address, possibly followed by a four or six byte password."

The what?

A magic packet is sent out and if the MAC address of the machine you are trying to reach is the same as the one you sent out - it turns on.

Usually. It is not 100% - and it sometimes will not work if your machine crashed or otherwise did not shutdown gracefully.

I highly suggest taking a look at the Wikipedia entry. It has software programs, descriptions and links.

Keep in mind that you will most likely need to delve into your BIOSes to enable WOL. Many older computers do not support this and most cheap NICs also do not. Most newer computers with integrated NICs will support WOL, so you might want to give it a go.

http://en.wikipedia.org/wiki/Wake-on-LAN

Another, admittedly lower tech option is to simply reroute all of the power buttons to a central location. I recently did this with some buttons, an enclosure, some spare ethernet cable and a few diodes - plus a lot of time soldering. This helps when you need to hard reboot a system, turn one on that refuses to respond to a magic packet, or turn on every system at the press of a single button. Power buttons on computers serve one purpose, to short the pins to ground. You can simply route a SPST NO (single pole, single throw, normally open) switch to a reasonable distance (up to several hundred feet, I would imagine) and press it to turn the machine on. For extra fun, enjoyment and female admiration (hah right) - also wire up the power LEDs remotely.

Wiring up another button to turn them all on at once is more than I care to write up. To do so, you need a few cheap diodes - diodes act as one way "valves" if you will, only allowing electricity to travel one way. Without diodes, you would not be able to boot individual machines without booting them all - if they were connected to individual buttons and a single "turn all on" button.

Another (somewhat jury rigged) option is to place them all on a power switch (make sure it is rated properly or just use the breaker). Set the BIOSes to resume on power resumption and they SHOULD power on once power is applied. This can be finicky sometimes to setup but usually works pretty reliably.