Docs / Wake-on-LAN

Wake a PC on your local network.

Wake-on-LAN isn't a magic NodalDesk feature: it's a capability of the network card and the motherboard. NodalDesk can send the right signal; the machine and the network have to be ready to accept it. Today it wakes machines within the same local network, not by powering them on from anywhere on the internet.

Back to docs Common problems

How it works

The magic packet.

The actual power-on is done with a Wake-on-LAN UDP packet: six FF bytes followed by the machine's MAC address repeated sixteen times. In NodalDesk, the WoL helper computes the MAC and the broadcast address of the primary interface when it can, and sends that packet over UDP broadcast to the standard port 9.

The nodaldesk-daemon has a separate responsibility: to stay as relay presence and listen for wake requests so it can send the magic packet on the local network. The technical docs place it on UDP 9877 for those orders, and the final send is still the WoL packet to the LAN.

Enable it in BIOS or UEFI

Look for a board option like Wake-on-LAN, PCIe wake, Power on by LAN or similar. The name varies by manufacturer. Without it, the system may shut the network card down entirely.

Allow waking from the system

The operating system can also block the wake. On Linux it depends on the interface and the power settings. On laptops, some deep-sleep modes don't keep the network ready to receive packets.

Use wired networking if you can

Wake-on-LAN is far more reliable over Ethernet. Waking over Wi-Fi depends on hardware, drivers and power saving, and on many machines it simply doesn't stay listening.

Keep the host's MAC

NodalDesk publishes the MAC when the host can detect it. If the client has no stored MAC, it can't build the magic packet for that machine.

Android

Waking from your phone.

The Android app includes Wake-on-LAN sending. Before sending the packet, it checks that the phone is on Wi-Fi; then it sends the broadcast to 255.255.255.255:9, waits a few seconds and checks whether the host responds. It also uses Wi-Fi and multicast locks to reduce cases where Android cuts the broadcast.

If you're away from home, you need a piece inside the network able to send the local packet; without it, there's no real remote power-on from outside.