Does Wake-on-LAN work when computer is off?
Wake-on-LAN (WOL) is a widely used feature that enables a computer to be turned on or awakened from sleep mode remotely, using a network. In this article, we’ll explore the question of whether WOL works when a computer is completely turned off.
Direct Answer:
To answer the question directly, WOL can work even when a computer is off, but only under specific conditions. For a computer to be turned on remotely using WOL, it must be in a state that allows the network card to receive and respond to Wake-on-LAN packets.
States That Allow Wake-on-LAN:
A computer can be in one of the following states to receive WOL packets:
• Standby: This state is also known as sleep mode or idle mode. In this state, the computer’s power supply is still connected, but the CPU, memory, and other components are in a low-power state.
• Hibernate: This state is also known as shutdown or turn off. However, when a computer hibernates, it preserves the current system state in RAM, so it can resume from the exact point of shutdown. The network card is still operational, and WOL packets can still be received.
• Off: Although a computer can be turned off completely, it is possible to awaken it using WOL packets if the power supply and network card are still functioning. However, this depends on the BIOS settings, as we’ll discuss later.
BiOS Settings:
The BIOS (Basic Input/Output System) plays a crucial role in determining whether WOL works when a computer is off. When a computer is powered off, it can be awakened using WOL packets if the following conditions are met:
• Wake-on-LAN (WOL) must be enabled in the BIOS: This feature must be enabled in the BIOS setup, which usually requires resetting the BIOS settings to the default or saving the current settings and then restarting the computer.
• Link power management (LPM) must be disabled or set to off: If LPM is enabled, the network card may go into a low-power state, preventing it from receiving WOL packets.
Table: Wake-on-LAN (WOL) Settings in BIOS
| BIOS Setting | Recommended Setting for WOL |
|---|---|
| Wake-on-LAN (WOL) | Enable |
| Link Power Management (LPM) | Disable or set to off |
Troubleshooting Tips:
If you’re experiencing issues with WOL not working when your computer is off, consider the following troubleshooting tips:
• Check the link light: If the link light is off, the network card is not operational, and WOL will not work.
• Verify the network card configuration: Ensure that the network card is set to obtain an IP address automatically, and that it is enabled in the network settings.
• Disable any energy-saving features: Some features, such as power management or energy-saving modes, may prevent the network card from functioning correctly.
Conclusion:
In summary, WOL can work even when a computer is off, but only if the computer is in standby, hibernation, or the BIOS settings allow it. Make sure to enable WOL in the BIOS and disable link power management to ensure that WOL works as expected.
Frequently Asked Questions:
- Does Wake-on-LAN (WOL) work on all computers?
No, WOL does not work on all computers. The computer’s network card must support WOL, and the BIOS must be set to enable it.
- Can WOL work on computers running on batteries?
No, WOL cannot work on computers that are running on batteries or are powered off. This is because the network card is not operational when the computer is in this state.
- Can I use WOL to control multiple computers remotely?
Yes, you can use WOL to control multiple computers remotely by setting up multiple network connections and configuring WOL settings for each computer.
- Is Wake-on-LAN (WOL) a secure method of remote control?
Yes, WOL is a secure method of remote control as it uses encryption and secure protocols to prevent unauthorized access.
- Can WOL be used to wake a computer from deep sleep mode?
No, WOL cannot wake a computer from deep sleep mode. WOL can only wake a computer from standby or hibernate mode.