Wake-on-LAN

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Wake on LAN (WOL, sometimes WoL) is an Ethernet computer networking standard that allows a shut-down computer to be booted remotely.

1 History
2 Technical details
3 Wake-on-LAN programs
4 See also
5 Additional resources

[edit] History

In April of 1997, the IBM Advanced Manageability Alliance released the first glimpse of Wake on LAN technology. Other industry initiatives, such as Intel-based Wired for Management, soon supported the standard.

[edit] Technical details

[edit] System requirements - IBM PC Compatible

Wake-on-LAN cable connectors.

Wake on LAN (WoL) support is implemented in the motherboard of the computer. The motherboard must have a WAKEUP-LINK header onboard and connected to the network card via a special 3-pin cable; however, systems supporting the PCI 2.2 standard coupled with a PCI 2.2 compliant network adapter typically do not require a WoL cable as the required standby power is relayed through the PCI bus. Most modern motherboards with an embedded Ethernet controller also support WoL.

Wake on LAN must be enabled in the Power Management section of the motherboard's BIOS. It may also be necessary to configure the computer to reserve power for the network card when the system is shut down.

In addition in order to get WoL to work, it is sometimes required to flash this feature to the card. You can do this in Windows from the properties of the network card in the device manager, on the "Power Management" tab. Check "Only allow management stations to wake up the computer" to make sure it does not wake up on every single network activity that occurs. For Linux, there is a FAQ available concerning this issue.

[edit] How it works

The general process of waking a computer up remotely in a LAN can be explained thus:

The target computer is shut down, with power reserved for the network card. The network card listens for a specific packet, called the "Magic Packet". The Magic Packet is broadcast on the broadcast address for that particular subnet or the entire LAN. The listening computer receives this packet, checks it for the correct information, and then boots if the Magic Packet is valid.

[edit] Magic Packet

The Magic Packet is a broadcast frame, transmitted over port 0 (Historically the most common port used), or 7 or 9 (becoming the most common ports used). It can be sent over a variety of connectionless protocols (UDP, IPX) but UDP is most commonly used. The data that is contained in a Magic Packet is the defined constant as represented in hexadecimal: FF FF FF FF FF FF followed by sixteen repetitions of the target computer's MAC address, possibly followed by a four or six byte password.

[edit] Wake-on-LAN programs

There are a number of programs available that make use of Wake-on-LAN. Below is a partial list.

[edit] Scripts

WOL Python – a Python script.
Wakeonlan – a Perl script that sends magic packets.
Wake-on-LAN Tutorial, with PHP script
Wake-on-LAN PHP script

[edit] Cross-platform

Remotewakeup.com - Start your computer over the Internet
DSLReports.com - Wake Me Up - A free WOL packet generator, does not require Java. The tool will also remember your targets if you are a registered member. You must have UDP port 9 forwarded in your firewall.
Depicus – Free WOL tools to send a WOL packet from different programming environments, including WOL command line, WOL for Windows, WOL for ASP, WOL over the Internet, WOL Com (VB/PHP), WOL for Windows 3.1, WOL Pocket PC 2002/3, WOL for Apple Mac, WOL Monitor/Sniffer, Mac Address Arp Viewer
java WOL – OS independent Java WOL utility which can be launched from browser.
JWakeME A Java MIDlet based Wake on LAN utility. Requires a MDIP 1.0 compliant device.
HyperWRT - Firmware for Linksys wireless routers with WOL GUI.
DD-WRT - Firmware for Linksys wireless routers with WOL GUI.

[edit] Source code

Here you can find source code about WOL functionality for different languages and platforms

WOL .net - A VB.NET class to wake a device on the network.

[edit] Microsoft Windows

Intellipool Network Monitor - Network and Server monitoring software that can start computers with wake-on-lan on a schedule.
SoftPerfect Network Scanner - A free multi-threaded IP, NetBIOS and SNMP scanner with a modern interface and several advanced features including Wake-On-LAN and remote shutdown.
Specops Gpupdate (Special Operations Software) - A free Active Directory Add-On. Specops Gpupdate gives you wake-on-lan, restart, shutdown and gpupdate through your Active Directory Users and Computers GUI.
Depicus Wake-On-Lan Windows Graphical User Interface - Free and simple WoL tool.
FUSION WakeUp on Lan - A free Windows application. Using FUSION WakeUp on Lan you can take advantage of turning on a remote PC through the net interface. Windows 98, ME, NT, 2000, XP or 2003.
WOL - Magic Packet Sender – A free Windows application to store MAC addresses and send Magic Packets. Requires .NET runtime
AMD PCnet Magic Packet Utility - mpusergd.pdf
WakeOnLan (AquilaTech) - A free Windows WakeOnLan program that is full featured. WakeUp, Shutdown, Ping, global shutdown all in one. Requires .NET runtime
MC-WOL - Command line wake on lan utility.
AMD PCnet Magic Packet Utility - This Windows application comes from AMD, the father of the Magic Packet. It a simple interface and a few nice features (like group announcements and scheduling).
Shirilla.com PowerState - A free Windows WakeOnLan program that requires .NET runtime. It also has Windows WMI shutdown features. Very easy to use.
WOL 1.0.3 - Freeware Wake-On-LAN tool for all windows versions.