Modern technologies do not tire of developing and delighting users. For example, today it has become possible to turn on a personal computer at a distance without any effort. There is such a function (WOL) for a long time, but not all users know how it works, and why it is needed.
Wake-on-Lan: what is it?
This protocol is designed to remotely turn on a computer that has a standby voltage supply on the motherboard, due to which the power supply can be started. Via WOL, an additional possibility of waking up from a wireless network is configured, if the router supports it.
You will need a similar function to perform a scheduled update of OS components and backup on computers that are outside the user's physical reach without the ability to turn it on yourself.
Since modern PCs provide power to the motherboard in the off state, the work of Wake-up-On-Lan with proper configuration is usually not satisfactory.
Principle of operation
For WOL, only two computer components are important: the motherboard and the network card. The first one should be connected to an ATX-compatible power supply, allowing the LAN adapter to view all packets coming to it. If one of them contains a special command containing the MAC address of the network card, it will send a signal to start powering the PC.
Otherwise, Wake-On-Lan (a program for remote launch) does not require downloading additional utilities: this feature is configured through the BIOS.
Magic pack
The team mentioned above is called the Magic Packet. It is it that the network card must receive to activate the start of the computer. It contains the MAC address of the LAN adapter, repeated 16 times, and other required information.
This package can be sent from the OS, website or router using UDP ports 7 and 9. However, if there is no need for this function and the ability to connect a PC to the mains, it is better to deactivate it, since it negatively affects the battery level.
How to enable WOL
Older computer models, like some of the newer ones, have the Wake-On-Lan setup function in the BIOS. To do this, it is worth knowing English at least at the initial level, otherwise the user simply will not find WOL, because today this designation is not used in the basic input / output system.
Usually, you should look for something similar in the power management section, for example, the lines with the names Wake-Up by PCI device or Power on by Ethernet Card.
However, if the PC runs on OS Linux, the Ethtool utility will be required to run the function, which will check WOL support on the network card.
Customization
Since Wake-On-Lan Windows 7 supports along with older versions, you can enable the protocol through the user interface of this OS. To do this, through “Start” you need to find “Computer Management” and enter the “Device Manager” in order to find the network adapter in the list that opens .
Next, by clicking the right mouse button you need to call its context menu, open "Properties" and go to the "Advanced" tab. In the displayed list, the user must select the Wake on Magic Packet item and set its value to the on position. You do not need to restart the computer.
To send a request for inclusion, you need to know the MAC address, host name, subnet mask and port number used. Downloading a program for transmitting a magic package is simple. The network is replete with various utilities, as well as websites that perform this function online.
Router setup
This item is only needed if you turn on the PC via the Internet, and not the local network. This will require a permanent and unique IP address provided to the user by the provider. Otherwise, you will have to rent a static external IP address or use a dynamic DNS client , accessing the equipment through its domain name. An example setup is to set the NAT translation rule for the IP address used to connect to the Network: UDP, ports 7 and 9.
Next, you need to create a broadcast address for the router, which is also needed to send the packet. Then you need to connect to the equipment through a special client and enter the following commands:
- ip arp / user address / ff: ff: ff: ff: ff: ff;
- system config-save.
Then the router is rebooted, and the settings take effect.
Wake-on-Lan: TeamViewer
TeamViewer - software designed for remote access to a computer, which in combination with the configured WOL allows you to turn on the device at a distance with less effort. To do this, you need to take a few more steps, except for those described above: configure the firewall and the utility itself.
Having entered the firewall, you should select "Rules for incoming connections", and then - "Create a rule". In the window that opens, click on "For port" and "Next." Then, set the values for UDP ports 7 and 9, allow connection to them (and prohibit its publicity). Finally, all that remains is to name the rule and confirm the changes with the “Finish” key.
The first step in setting up TeamViewer is to link the computer to the account. This is required for security, since the software is not intended for illegal actions, therefore, the computer must belong to someone who wants to access it.
Account binding is carried out by entering the e-mail and password from the account in a special dialog box that the user can easily find by himself. Once the account is assigned to the PC, you will need to configure Wake-On-Lan through TeamViewer ID. This is useful if the device does not have a public address.
In the utility’s network settings, you need to find the “Incoming connections” item and change its value to “Accept”. Then, in the same section, you must select "Configuration", after which a dialog box appears with WOL wakeup functions. In “Other TeamViewer applications on your network”, the user must enter and add his ID.
How to disable WOL
As soon as the need for Wake-On-Lan disappears, it is better to turn off the utility to save battery power and to avoid interference with third-party equipment, sometimes arising from contact with the computer on which this function is enabled.
To do this, you will need to do the opposite of what appears in the "How to enable WOL" section of this article. However, before that, you need to go into the properties of the network card and uncheck all the checkboxes in the "Power Management" tab so that after shutting down the PC remains de-energized and cannot be turned on by a third-party request.
Then, in the "Advanced" section, the user must disable the launch of the device via Magic Packet, and to be sure of the success of the operation, it is worth deactivating WOL in the BIOS settings. This is done in the same branch as indicated above.
How to check the performance of WOL
It is possible to check the utility's performance only empirically, being directly next to the PC. This is done using TeamViewer or other third-party programs and resources to send the Magic Packet.
However, there is one not-so-pleasant moment: some devices with Wake-On-Lan configured and enabled to enable BIOS via the network start up their own power without sending and receiving a Magic Packet. The reason for this is the slightly increased functionality of Intel and 3COM network cards, which use not only WOL to send a signal to turn on a PC on a local network. They also involve other events: by default, as a rule, several criteria are set at once, on which awakening depends.
This problem is solved by changing the adapter settings through third-party software. You just need to remove the unnecessary conditions for the function to work correctly.