Waking a Mac up from sleep generally requires you tap a key on the keyboard, or click your mouse or trackpad; however, there are times when you might need to wake your Mac up remotely, either because it is locked away such as a server in a closet, or perhaps it is among a number on a large local network that you are trying to access and need it woken up.

Granted for servers, you might not want them to be set to sleep, but there are many instances where you might need to interact with workstation systems on a LAN.

Waking your Mac over the local network uses a technology called Wake on LAN, which can be configured in your Mac’s Energy Saver system preferences. If enabled, this allows your system to be woken from sleep or standby modes, using a special network datagram called a magic packet. This has been classically done by using one computer to wake another one; however, with the advent of iPhones and iPads, you can also do this with these devices, provided they are set up correctly.

To use this, you will first need to know some information about your Mac, and ensure it is set up to be woken through the network. This information is your Mac’s physical MAC address, and perhaps its IP address, depending on the waking tool you will be using.

The Setup

1. Configure the Mac to Wake on LAN by checking the “Wake For Network (or Ethernet/Wi-Fi) Access” in the Energy Saver system preferences.
2. Next, look up your Mac’s physical MAC address, and also note its IP address. These can be done in the Network system preferences.

Waking it up

1. Get an app for your iPhone or iPad that supports Wake on LAN. Some of these are Mocha WOL (free), and iNet WOL.
2. Launch the App and enter your Mac’s MAC address (and optional IP address) according to the program’s instructions.
3. Once configured, you should have an option to tap a button to send the datagram and wake your Mac up.

Keep in mind that this process will require your Mac to be on the same network as your iPhone, so this cannot be done over the Internet. If the process does not work, then double-check that you have the right MAC address for your Mac’s active network port.

To troubleshoot this feature not working, you can try resetting your router, and checking its settings to ensure Wake On LAN features are allowed (sometimes there may be settings that block this).