Wake-on-LAN
Wake-on-LAN powers on a machine that is asleep or off by sending it a “magic packet” over the network. Save the machine’s MAC address with its host once, and you can wake it from any of your devices: phones (Android, iPhone, iPad) and computers (Windows, macOS, Linux).
The machine itself must be set up to be woken this way, in its firmware and its network adapter’s settings.
Save the MAC address
Section titled “Save the MAC address”- Open the host’s editor.
- On a computer, choose Advanced in the editor’s side rail. On a phone or a tablet, and on a computer where the editor opens as a page of its own, choose Show advanced options.
- Under Wake on LAN, type the machine’s address in MAC address (optional), for example
00:00:5e:00:53:01. - Leave Broadcast address at
255.255.255.255to reach every machine on the network you are on, or see Waking a machine on another network. - Save the host.
Any common way of writing a MAC address works: 00:00:5E:00:53:01, 00-00-5E-00-53-01 (as Windows shows it), 0000.5e00.5301 or 00005E005301. What counts is the 12 hexadecimal digits. Anything else is refused with “Invalid MAC address”.
The MAC address and the broadcast address sync with the host, so every device you sync can wake it.
Wake a host
Section titled “Wake a host”Waking is offered only for a host with a MAC address saved.
On a computer:
- On the Hosts page, right-click the host and choose Wake (WoL).
- Or select the host: the panel beside the hosts has a Wake on LAN section with Wake (WoL).
- Or right-click the host in the Hosts panel beside your sessions and choose Wake (WoL).
On a phone: long-press the host and choose Wake.
ZestSSH then says “Wake-on-LAN packet sent to” and the host’s name, or why it was not sent (see Messages).
Connecting to a host does not wake it. Wake it first, give it time to start, then connect.
What ZestSSH sends
Section titled “What ZestSSH sends”The magic packet is 6 bytes of FF followed by the MAC address 16 times. ZestSSH sends it over UDP to the broadcast address on port 9, the port Wake-on-LAN uses:
- once the way your device’s system picks,
- and once from each IPv4 network your device has. A computer often has several (a VPN that takes the default route, virtual adapters), and a broadcast that leaves on the wrong one wakes nothing.
ZestSSH says the packet was sent only when at least one of these sends went out. Nothing answers a magic packet, so ZestSSH cannot tell whether the machine woke. To know, connect once it has had time to start.
Waking a machine on another network
Section titled “Waking a machine on another network”A broadcast to 255.255.255.255 reaches only the network your device is on. Other ways:
- The network’s own broadcast address, for example
192.0.2.255for the network192.0.2.0/24, when your device is on that network. - An address or a name that reaches the machine’s network, for example a router at
203.0.113.10orhome.example.comthat forwards UDP port 9 to that network. A name is looked up when you wake the host, for up to 5 seconds, and its first IPv4 address is used. - A machine that is on that network: connect to it and run a wake tool there, for example
wakeonlan 00:00:5e:00:53:01where that tool is installed.
Messages
Section titled “Messages”In these messages, <host> stands for the host’s name.
| Message | What it means |
|---|---|
Wake-on-LAN packet sent to <host> | The packet went out. It does not say the machine woke. |
Not sent: the address saved for waking <host> is not a MAC address. | The saved MAC address does not have 12 hexadecimal digits. Change it in the host’s settings, under Wake on LAN. |
Not sent: <address> is not an address, and no address was found for it as a name. | Broadcast address holds a name that could not be looked up, or text that is no address. |
Not sent: the port saved for waking <host> (<port>) is not a port. | The host carries a port outside 1 to 65535. |
| Not sent: no network of this device took the packet. | No send went out. Check that this device is on the same network as the machine. On an iPhone or iPad, also check that ZestSSH may use the local network (iOS Settings, Privacy & Security > Local Network). |
Where ZestSSH knows more about a failure, the message has its details to copy.
Limits
Section titled “Limits”- Port 9. The host editor has no field for another port.
- A woken machine is not reported. ZestSSH says the packet was sent, never that the machine is up.
- Hosts of a team’s vault that is closed on this device are not woken; ZestSSH says why in the vault’s own words.
- IPv6. A broadcast address that is an IPv6 address gets one send, the way the system picks.
Next steps
Section titled “Next steps”- SSH connections to connect once the machine is up.
- Cloud sync to take a host’s Wake-on-LAN settings to your other devices.