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Unwanted wake-up events may occur when you enable the Wake On LAN feature in Windows 7 or in Windows Vista
Article ID: 941145 - View products that this article applies to.
In Windows 7 and in Windows Vista, the Wake On LAN (WOL) feature can wake a remote computer from a power-saving state such as sleep. When you enable WOL, the network adapter continues listening to the network when the computer is asleep. WOL wakes the computer if it receives a special data packet.
One kind of special data packet contains a wake-up pattern. By default, Windows 7 and Windows Vista listen for the following packets when you enable WOL:
In most cases, a wake-up pattern or a Magic Packet enables remote access to a computer that is in a power-saving state. However, some networking protocols use these packets for other purposes. For example, routers use ARP packets to periodically confirm the presence of a computer. Such protocols do not use these packets to wake computers. However, in some networks, network traffic may wake up a remote computer by mistake. These unwanted wake-up events may occur in especially noisy environments such as enterprise networks. Therefore, by default, WOL is disabled in Windows 7 and in Windows Vista.
WOL can be an effective way to conserve power while keeping a computer reachable on the network.
However, unwanted wake events may occur after you enable WOL. For example, the computer may wake up soon after it enters a power-saving state. One cause may be that the network environment generates wake-up patterns too frequently. In this situation, we strongly recommend that you configure the computer to wake only in response to Magic Packets. Magic Packets are especially designed to wake up a computer from a power-saving state. Also, because a Magic Packet is specific to the MAC address of a network adapter, a Magic Packet is very unlikely to be sent accidentally.
To configure Windows 7 in this manner, follow these steps:
You may also have to enable BIOS settings to enable WOL. The specific BIOS settings depend on the manufacturer of the computer.
Article ID: 941145 - Last Review: December 3, 2010 - Revision: 3.0