Does wake-on LAN/WOL depend on hardware or the operating system?

Does wake-on LAN/WOL depend on hardware or the operating system? Or both? How does one send a command to wake up a machine if it is supported (say a Fedora server)?

Hardware, and the associated firmware that runs on that hardware. It is OS independent.

There are a plethora of WoL utilities to send a "wake up" packet (sometimes called a Magic Packet). Try the port/package management system in your OS (or Google it). It's usually as easy as wol [MAC Address]

Wake On Lan involves sending a "magic packet" which contains the MAC address of the destination computer. There's a lot of detail here:

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

The best way to send a WOL request from one Linux box to another is ether-wake. If you're looking for it in Fedora, install the net-tools package:

$ yum whatprovides */ether-wake
net-tools-1.60-102.fc13.x86_64 : Basic networking tools
Repo        : fedora
Matched from:
Filename    : /sbin/ether-wake

The syntax is pretty darned easy:

ether-wake 00:11:22:33:44:55

Just replace 00:11:22:33:44:55 with the MAC address of the machine you want to wake.