I needed to share an Outlook user's calendar with someone else in her office. I had expected to be able to remotely log into her system to configure Outlook to share her calendar. But when I attempted to log into her system at 9:30 P.M., I found it was inaccessible. I then remembered that she always turns her system off when she leaves. I didn't want to spend 1/2 driving to her office to make a change I could complete in less than 10 minutes and then have to spend another 1/2 hour driving back home.
Fortunately, I had selected the option to have Dell preconfigure the system for Wake On Lan (WOL) support in the BIOS when her company purchased the system. Wake On Lan support allows one to restart a computer that has been shut down by sending a "Magic Packet" to the Media Access Control (MAC) address of the network card in a computer to "wakeup" the computer, i.e. power on and boot up the computer.
This can occur when the system is still providing power to the Ethernet controller in the system. Most modern computers with a network connection provided through the motherboard support this functionality. The functionality is also present in motherboards that support the PCI 2.2 standard when a PCI 2.2 network adapter is used. In other cases, when WOL support is provided through the motherboard, the motherboard must have a WAKEUP-LINK header onboard and connected to the network card via a special 3-pin cable. Wake on LAN must also be enabled in the Power Management section of the systems's BIOS. It may also be necessary to configure the computer to reserve power for the network card when the system is shut down.
To wake a shut down system, you need a program that can send the Magic Packet to the MAC address of the target system. You also need to know the MAC address of the target system. In this case I use Norton Ghost to backup the systems on the LAN and Norton Ghost provided me with the MAC address.
There are quite a few free programs that provide WOL capabilities. You can find many listed in the Wikipedia Wake-on-Lan article on the topic. I used the free utility provided by MATCODE at http://www.matcode.com/wol.htm.
To use the MATCODe WOL utility, mc-wol.exe, you simply download the utility
and then run it with mc-wol <MAC Address>
, e.g.
as shown below.
C:\Program Files\Network\WOL>mc-wol 00:13:72:3B:4A:B6
WakeOnLAN v1.0 Copyright (c)2001, MATCODE Software.
Web: http://www.matcode.com
Author: Vitaly Evseenko, ve@matcode.com
Sending "Magic Packet" to 00:13:72:3b:4a:b6 - Success!
Once I ran the program, I was able to ping the IP address of the target system shortly afterwards to verify the system was back up.
If you need to obtain the MAC address of a system you can ping it and then
look in the ARP table
on the system from which you ran the ping, with arp -a
to find the
relevant entry. Or you can use the MATCODE, MCGETMAC.EXE
utility available from the same URL as the MC-WOL.EXE
utility
or from the links listed below.
C:\Program Files\Network\WOL>mcgetmac 192.168.0.15
Get MAC v1.0 Copyright (c)2001, MATCODE Software.
Web: http://www.matcode.com
Author: Vitaly Evseenko, ve@matcode.com
Name: js.example.com
IP address: 192.168.0.15
Ethernet MAC address: 00:13:72:3B:4A:B6
Press any key ...
References: