etc. The 3-pin WoL interface on the motherboard consist of pin-1 +5V DC (red), pin-2 Ground (black), pin-3 (green or yellow). By supplying the pin-3 wake signal with +5V DC the computer will be triggered to power up provided WoL is enabled in the BIOS/UEFI configuration. Software requirements Software which sends a WoL magic packet is referred to in different circles as both a "client" and a "server", which can be a source of confusion. While WoL hardware or firmware is arguably performing the role of a "server", Web-based interfaces which act as a gateway through which users can issue WoL packets without downloading a local client often become known as "The Wake On LAN Server" to users. Additionally, software that administers WoL capabilities from the host OS side may be carelessly referred to as a "client" on occasion, and of course, machines running WoL generally tend to be end-user desktops, and as such, are "clients" in modern IT parlance. Creating and sending the magic packet Sending a magic packet requires knowledge of the target computer's MAC address. Software to send WoL magic packets is available for all modern platforms, including Windows, Macintosh and Linux, plus many smartphones. Examples include: Wake On LAN GUI, LAN Helper, Magic Packet Utility, NetWaker for Windows, Nirsoft WakeMeOnLAN, WakeOnLANx, EMCO WOL, Aquila Tech Wake on LAN, ManageEngine WOL utility, FusionFenix and SolarWinds WOL Tool. There are also web sites that allow a Magic Packet to be sent online without charge. Example source code for a developer to add Wake-on-LAN to a program is readily available in many computer languages. The following example is in Python 3: import socket def wol(lunaMacAddress: bytes): s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1) magic = b'\xff' * 6 + lunaMacAddress * 16 s.sendto(magic, ('<broadcast>', 7)) if __name__ == '__main__': # pass to wol the mac address of the ethernet port of the appliance to wakeup wol(b'\x00\x15\xB2\xAA\x5B\x00') Ensuring the magic packet travels from source to destination If the sender is on the same subnet (local network, aka LAN) as the computer to be awakened there are generally no issues. When sending over the Internet, and in particular where a NAT (Network Address Translator) router, as typically deployed in most homes, is involved, special settings often need to be set. For example, in the router, the computer to be controlled needs to have a dedicated IP address assigned (aka a DHCP