WOL Wake On LAN

Have a Linksys Router you're trying to get working with WOL?

Wake On LAN

Wake On LAN (Local Area Network, this is your group of computers) is functionality that allows you to turn your computer on by sending a specially built message to it.

If you're a computer geek Wake On LAN is functionality supported either by your motherboard or your operating system and your NIC (Network Interface Card - this is what you use for your Internet Connection) that listens for special packets called Magic Packets that it then uses to power on or wake up from a non-interactive state.

Wake On LAN can wake up windows from sleep (s3) or hibernate (s4) but you're looking for motherboard support if you want to power on your computer from a shut down state (s5). What are those s numbers?

Magic Packets

Magic Packets are specially formed UDP packets that signal a specific NIC to send a wake command to the computer. The structure of these packets is a 6 byte header (all ones - so FF FF FF FF FF FF in hex) and the MAC address of the computer to be woken up repeated 16 times for a total of 102 bytes.

MAC Address

A MAC address (Media Access Control address) is a special and mostly unique identifier for NIC Cards. Typically it is 6 Bytes long with the first 3 bytes being used to identify the make of the NIC Card and the last 3 bytes being used to identify your specific card. It's important to note that these MAC addresses or Physical addresses are not guaranteed to be unique, or in other words they can be reused.

Finding your MAC Address and Subnet Mask

The first thing you want to do if you're interested in WOL (Wake On LAN) is get some information about your computer. You can do this a couple of ways, through a command prompt, or through Windows Network Connections, and you may need help from another computer on the internet for your external IP address.

First go to Start>Control Panel>Network Connections. There should be a default one named Local Area Connection. Right-click this icon and choose Status. The choose the Support tab. Then click the Details button. Write down your Physical Address (This is your MAC Address) and Subnet Mask.

If you're doing it from a command prompt I'm going to assume you know what one is and how to launch it etc etc. The command you want to type in is ipconfig /all and you will see information about the various NICs installed in your computer. Look for Ethernet adapter Local Area Connection: as this is the default for a windows internet connection and find the Physical Address (something like 00-00-00-00-00-00), and the Subnet Mask (something like 255.255.255.0).

Finding your Internet-Exposed IP Address

The easiest way to do this is to go to http://www.benfinnigan.com/WOL/whatismyip.asp and write down the IP address it returns. There shouldn't be anything else on the page.