Wake on LAN

The Wake on LAN (WOL) page at Services > Wake on LAN can wake up computers from a powered-off state by sending special “Magic Packets”.

The network interface card in the client computer that is to be woken up must support WOL and it must be configured properly. Typically there is a BIOS setting to enable WOL, and non-integrated adapters often require a WOL cable connected between the NIC and a WOL header on the motherboard.

WOL has many potential uses. Typically, workstations and servers are kept running because of services they provide, files or printers they share, or for convenience. Using WOL would allow these to remain in a sleep state to conserve power. When a service is required, the system can be woken up when needed. Another example would be if someone needs remote access to a system, but the user shut it down before leaving the office. Using WOL the target system can be awoken, and it may then be accessed once it has booted.

Warning

WOL offers no inherent security. Any system on the same layer 2 network may transmit a WOL packet, and the packet will be accepted and obeyed. It is best to only configure WOL in the BIOS for machines that need it, and disable it in all others. There are some vendor-specific WOL extensions that provide extra security, but nothing universally supported.

Wake Up a Single Machine

To wake up a single machine:

  • Navigate to Services > Wake on LAN
  • Select the Interface through which the target system can be reached
  • Enter the target system MAC address in the format of xx:xx:xx:xx:xx:xx
  • Click Send

pfSense will transmit a WOL Magic Packet out the chosen interface, and if everything went as planned, the system will power on and start to boot. Keep in mind that systems will take some time to boot. It may be several minutes before the target system is available.

Storing MAC Addresses

To store a MAC address for convenience:

  • Navigate to Services > Wake on LAN
  • Click fa-plus Add under the list of stored MAC addresses to add a new entry
  • Select the Interface through which the target system can be reached
  • Enter the target system MAC address in the format of xx:xx:xx:xx:xx:xx
  • Enter a Description for the entry, such as the target system’s name, owner, or location. For example: “Pat’s PC” or “Sue’s Server”
  • Click Save

Once saved, the entry will be available on the list at Services > Wake on LAN.

Maintaining the entries is similar to other tasks in pfSense: Click fa-pencil to edit an existing entry, and click fa-trash to remove an entry.

Wake a Single Stored Machine

To send a WOL Magic Packet to a system that has been previously stored:

  • Navigate to Services > Wake on LAN
  • Locate the desired entry in the list
  • Click its MAC address or click the fa-power-off icon in the Actions column

The WOL page will reload, and the Magic Packet will be sent. The status of the WOL attempt will also be displayed.

Wake All Stored Machines

To send a WOL Magic Packet to all stored systems at once:

  • Navigate to Services > Wake on LAN
  • Click fa-power-off Wake All Devices under the list of stored addresses.

Wake from DHCP Leases View

To send a WOL Magic Packet from the DHCP Leases view:

  • Navigate to Status > DHCP Leases
  • Locate the desired system in the list
  • Click fa-power-off at the end of the lease row to send a WOL Magic Packet

Note

The WOL function is only available for systems marked offline, meaning they are not in the ARP table on the firewall. If a system was very recently powered off, it can take a few minutes for the ARP entry to expire before it will be marked offline.

If a system has been powered off for quite some time, clicking fa-plus-circle Show all configured leases might be required to see the previous lease.

When the link is clicked, the browser will return to the WOL page, and the Magic Packet will be sent.

Save from DHCP Leases View

A MAC address and hostname may be copied to a new WOL mapping entry while viewing the DHCP leases.

  • Navigate to Status > DHCP Leases
  • Locate the desired system in the list
  • Click fa-plus-square at the end of lease entry
  • Confirm the values on the page, and enter any missing information.
  • Click Save