Wake On Lan (for Ubuntu)

1. BIOS: Power - APM Configuration - Power On by PCIe Devices -> [Enable]
2. BIOS: Power - APM Configuration - Power On by PCI Devices -> [Enable] 

3.

cd /etc/init.d/
touch wakeonlanconfig

#!/bin/bash
ethtool -s eth0 wol g
exit

chmod a+x wakeonlanconfig

update-rc.d -f wakeonlanconfig defaults

4. On other PC:

wakeonlan 01:23:45:67:89:ab

Source: http://ubuntuforums.org/showthread.php?t=234588&highlight=wake+lan