Wake-On-LAN

Wake-On-LAN

Wake-On-LAN (commonly called WOL) is the basic concept of enabling or starting a remote computer without having to press the power button as usual. In this article we will look at how Wake-on-LAN works and how to activate it.

What is Wake On LAN?

In essence, Wake On LAN is an industry standard protocol that is used to boot computer systems in extremely low power mode. The concept of low power mode is that we can understand that the computer is in a completely off state, but is still accessing the power supply. This protocol also adds Wake-on-Wireless-LAN functionality.

This is useful if you want to remotely access your computer for any purpose: It allows you to maintain access to files and applications, while your computer is kept in a low power state. electric bill). If you use the VNC or TeamViewer software regularly, or manage the data server, then Wake-on-LAN is much more convenient.

WOL depends on two main factors: mailboard (motherboard) and network card (network card). Specifically, your motherboard must be connected to a compatible ATX power supply, network adapter or wireless must support this feature. Because WOL is set up via the BIOS or the firmware of the network card, we do not have to use any other software to activate and configure it. However, you do not need to worry because most of the computer models, today’s motherboard has been integrated with this ability, even with the dedicated motherboard form, we can also set the time automatically. turn on and off.

And if you have to buy more network cards in the case of mainboard does not have built-in components, please fully understand the support WOL.

How does Wake-on-LAN WOL work?

Computers with Wake-on-LAN enabled will wait for a packet containing the MAC address of the network card, called the incoming Magic Packet. These Magic Packets are sent by specialized software, made for each platform or sent by a router or Internet-based website. Typical ports used for these Magic Packets are UDP 7 and 9. Since the host computer is actively waiting for packets, the power will have to be allocated to the network card, causing the laptop battery to drop faster, so if To save battery power without using WOL, you should temporarily turn it off.

Magic packets are routinely sent over the entire network and include complete information about the subnet, network broadcast address, MAC address of the network card on the target computer. The screenshot above is the result obtained from the packet magic packet with a packet sniffer tool, which can raise concerns for users using WOL over an insecure network or on the Internet. Common family, you can use without worry. Many well-known mainboard manufacturers include a number of support tools that come with WOL to meet the needs of the user, depending on the specific situation.

Activate WOL on Windows

To use Wake-on-LAN you have to enable it in several places – usually the BIOS and in Windows. Let’s start with the BIOS.

With BIOS:

Hầu hết các mẫu mainboard hiện nay đều có sẵn phần tùy chọn WOL trong BIOS. Trong khi khởi động, các bạn nhấn phím Escape, F2, hoặc Delete để truy cập BIOS, sau đó tìm trong phần Power Management hay Advanced Options hoặc tương tự:

Most motherboard models now have WOL options available in the BIOS. While booting, you press Escape, F2, or Delete to access the BIOS, then look in Power Management or Advanced Options or similar:

The screenshot above was taken from the HP laptop, the WOL option underneath the After AC Power Failure section in Power.

With some ASUS models, the Wake on LAN option is “buried deep” in the menu system, under Power on by PCIE / PCI, because the integrated network controller is behind the PCI controller.

Either way, many computer models do not have this option, or are too coarse to find it, but that does not mean we can not use WOL, instead you have to use the built-in customization function. operating system.

With Windows:

Click Start, open the Device Manager section and expand the Network Adapters section, right-click on the network adapter and select Properties> Advanced tab.

In the window that appears, scroll down to find the Wake on Magic Packet option and change the value to Enable, leave the settings on Wake on, then click OK.

Now, you click on the Power Management tab and make sure that: Allow this device to wake up the computer and only allow a packet packet to wake up the selected computer. Click OK to finish.

With Mac OS X:

Open System Settings> Energy Saver. You will see Wake for Network Access or similar option, which will enable Wake-on-LAN.

With Linux:

In essence, this open source operating system has a very good tool to test if your system supports WOL or not. Open Terminal and install ethtool with the following command:

sudo apt-get install ethtool

Command Compatibility Check:

sudo ethtool eth0

Change the network adapter’s eth0 value to eth0 as the case may be:

Here, go to the Supports Wake-on, if marked with g, we can use magic packet for WOL. And to activate this option, you type:

sudo ethtool -s eth0 free g

Then type the command as above to check again, looking for the Wake on section, we will see the g option instead of d as above:

WOL Magic Packet submission process:

To send WOL request information, we can use the following options:

Depicus has developed a number of lightweight and multifunctional tools to accomplish this task, including command line and graphical interface, supporting a variety of operating system platforms. If you would like to learn more about this process, please refer to here, or this article.

And if you want to turn on your computer using Android phone using WOL, and PC Auto Waker tool:

The basic functionality of PC Auto Waker is based on the 802.11 Wifi standard. The setup process is encapsulated in 3 steps. First, you need to enter the name of the computer to boot (not necessarily coincide with the actual name of the computer) – this is the step to identify any computer in the system:

Then enter the corresponding MAC address of the computer. And finally, enter the SSID of the network you are using. When done, move your computer to Sleep or Hibernate, then try the Wake All button on the main console of PC Auto Waker. If everything works according to our wishes then everything is finished, and if something goes wrong or is not working, then you need to check out some of the basic settings above.