For WakeOnLan to work, you need the following items:

• A motherboard which supports resume on ring events
• A network card which suppots WakeOnLan
• Possibly a cable connecting your network card to the WOL header on your motherboard (unless it's an onboard NIC)

You will need to enable WOL in the machine's BIOS, and you will need to know the ethernet card's MAC address.

Then, (from another machine) you can use the ether-wake package to send the special ethernet frame. On debian: apt-get -u install etherwake.

Then from the command line, you can do

$ ether-wake <macaddress>

Or you can add an entry to /etc/ethers with macaddress to hostname entries and just do

$ ether-wake <hostname>

(Note that the version of etherwake in Debian Woody doesn't seem to support this)

Some network card drivers seem to disable the WOL ability of a network card. If you can use WOL just after you've booted into Windows, but not at all after you've booted into Linux, this probably applies.

There is a program called ethtool which you can use to fix this. It'll need to be applied every boot, so stick it in rc.local or somewhere.

 ethtool eth0
 Settings for eth0:
        Supports Wake-on: g
        Wake-on: d
        Link detected: yes

This shows that it supports MagicPacket WakeOnLan (type g), but it is disabled at the moment (Wake-on: d). You can fix this by running

 ethtool -s eth0 wol g
 ethtool eth0
 Settings for eth0:
        Supports Wake-on: g
        Wake-on: g
        Link detected: yes