What is remote wake-up?
The ability to remotely wake computers is an important development in computer management. The feature has evolved from a simple remote power-on to a complex system able to interact with many devices and operating system (OS) power states.
Early implementations required the system to have a standby power supply. The system could start from a powered off state by sending a Magic Packet*. By toggling a signal connected to the computer power control circuitry, the adapter responds to a Magic Packet that has its own MAC address. The power control circuitry, in response, activates power resulting in the computer starting the OS.
The ability to power on the computer allowed network administrators to complete off-hours maintenance at remote locations without sending a technician. This early implementation did not require an OS that was aware of remote wake-up.
APM provided BIOS-based power control. Newer computers feature Advanced Configuration and Power Interface (ACPI), which extends the APM concept to allow the OS to selectively control power by individual components.
ACPI supports many power states. Each state represents a different level of power, from fully powered up to completely powered down, with partial levels of power in each intermediate state. Here is a summary of the power states:
- S0 - On and fully operational.
- S1 - System is in low-power mode (sleep mode). The CPU clock stops, but RAM powers on and refreshes.
- S3 - Suspend to RAM (standby mode). Most components shut down except RAM.
- S4 - Suspend to disk (hibernate mode). The memory contents swap to the disk drive, and then reload into RAM when the system wakes.
- S5 - Power off.
ACPI aware operating systems, such as Microsoft Windows 98*, Windows Me*, Windows 2000*, Windows XP*, and Windows Vista*, support remote wake-up from standby or hibernate mode.
Wake-up packets are typically sent by network management programs, though simple programs can be used for this purpose (available on the Internet at no charge).
You need to configure specific BIOS settings to enable remote wake-up on your system.
- In both APM and ACPI computers, settings for Wake on LAN (WOL), generally display under the Power Control area, and are titled Wake on LAN or Wake on PME. To allow remote wake-up, enable the setting that corresponds to your adapter connection.
- Systems using an ACPI aware OS (such as Windows* XP), can power up the system from a power off state, by enabling ACPI-specific settings such as Wake on LAN from S5.
- Many ACPI computers can be configured to work in APM mode. Check your BIOS settings to verify your operating mode.
Multiport Ethernet adapters
Wake on LAN is supported on port A only on most multiport adapters. See the software release notes (readme.txt) for a list of adapters that support Wake on LAN on port A only.
10-Gigabit Ethernet adapters
Wake on LAN is not supported on Intel® Ethernet 10-gigabit adapters.
Operating system settings
The Magic Packet format is not the only packet type that can initiate the remote wake feature. For other packet types, see operating system settings below.
Non ACPI-capable Microsoft Windows* products
Microsoft Windows NT* and Windows 95* are not ACPI-capable. Some settings are not available in these operating systems.
ACPI-capable Microsoft Windows* products
Microsoft Windows 98, Windows Me, Windows 2000, Windows XP, Windows Vista, and later versions of Windows are ACPI-capable. In some ACPI-capable computers, the BIOS has a setting that allows you to wake from an S5 state, but most of these operating systems only support remote wake from standby.
|Enable wake from shutdown by Magic Packet|| |
|Enable wake from standby|| |
- Power on the computer
- Invoke the Intel® Boot Agent configuration utility by entering CTRL-S when the Intel Boot Agent prompt displays on the screen.
- Enable the Legacy OS Wakeup Support. The adapter can then respond to a Magic Packet wake up event.
|Note||The Legacy OS Wakeup Support parameter was not available in early versions of the Intel Boot Agent. To update your Intel Boot Agent to the latest version, download PREBOOT.EXE and follow the included instructions.|