Remote System Power-up with Wake On Lan (WoL)
I decided to test out WoL today, and I got it working with linux and openbsd.
WoL is a standard mechanism for remotely powering on systems - if a compatible network card hears a magic packet, it turns on the system power. The magic packet is the card's mac address repeated 6 times.
You need three things to make it work: a compatible motherboard, a compatilbe network card, and a little cable to connect the two. Basically the card uses the cable to press the motherboards power button.
I used a free perl program called wakeonlan on my openbsd gateway, and it wokred fine. One caveat is that you have to have acpi enabled in the bios, this was not immediately apparent in the bios config screen.
This is useful to me because I like to power off my desktop system when I'm not using it. I leave my gateway/firewall on 24/7. This way if I'm in a remote location and need to access my desktop machine, I can ssh to my gateway and fire it up via WoL. Wat a few minutes and my desktop is operational.
I could also implement a scheduled on/off cycle for the desktop machine via a cron job on the desktop system that shut the machine down via apm and a cron job on the gateway that turned it back on.
Remember, you must have ACPI enabled in your system BIOS.