Macs include a built-in way to remotely access your Mac’s files and its screen from anywhere in the world. The “Back to My Mac” feature is free but only works between Macs.
While Microsoft discontinued the similar features offered by Windows Live Mesh and left Windows users with basic OneDrive syncing, Apple still supports the old Back to My Mac service and rolled it into iCloud.
Enable Back to My Mac
Back to My Mac is part of iCloud. It doesn’t actually store your files or other sensitive data in the cloud. Instead, it uses your iCloud user account (Apple ID) to associate your Macs. To connect to a Mac, you must have logged into each Mac with the same iCloud account.
On each Mac you want to use, open the System Preferences window by clicking the Apple icon and selecting System Preferences. Click iCloud and ensure the “Back to My Mac” check box is enabled.
Note the iCloud account you’re using here. To remotely access your Mac from another Mac, you must log into that other Mac with the same iCloud account. Even if you don’t own the Mac, you can create a new user account on it and log in with your iCloud account.
Activate File and Screen Sharing
Back to My Mac allows you to share a Mac’s files and screen. This lets you remotely access any single file on your Mac, or use “screen sharing” to remote-desktop into your Mac and use it as if you were sitting in front of it.
To use these features, you’ll need to ensure both File Sharing and Screen Sharing are enabled on a Mac. From the System Preferences window, click the Sharing icon and enable Screen Sharing and File Sharing.
You’ll need to do this on each Mac you want to remotely access via Back to My Mac.
Router Configuration
For best connectivity and maximum performance, Apple recommends you enable the UPnP or NAT-PMP features on your router. This allows your Mac to automatically forward the ports it requires for connectivity.
Configure these options from your router’s web interface.
Remotely Access a Mac’s Files and Screen
With Back to My Mac, File Sharing, and Screen Sharing enabled, you should now be able to remotely connect to your Mac. Log into another Mac with the same iCloud account you used to log into the first Mac you set up. You can do this from anywhere in the world as long as you have an Internet connection.
When you open the Finder, you’ll see all the Macs you’ve signed into and enabled Back to My Mac on under Shared in the sidebar. Click a Mac’s name to access its files — you can browse its entire drive and grab any file from the Finder window.
To remotely access a Mac’s screen, click the Mac in the Finder’s sidebar and click the “Share Screen” button at the top of the window. Your Mac will immediately establish a screen-sharing connection with the other Mac, and you’ll see its desktop in a window on your current Mac. You can remotely control the Mac as if you were sitting in front of it.
If Your Mac is Sleeping
If the remote Mac is in sleep mode, you won’t normally be able to access it over the network. If you’d like to remotely access a Mac and initiate connections while it’s in sleep mode, the “Wake on Demand” feature can help. You’ll require a device that can function as a “Bonjour Sleep Proxy,” which will tell the Mac to wake up when you try to connect. Apple’s AirPort Base Station, Time Capsule, and Apple TV can all function as a sleep proxy, waking up your Mac when you try to connect to it over the Internet.
Back to My Mac actually uses something called “Wide-Area Bonjour” to securely discover and connect to services over the Internet. Other Bonjour-enabled services — not just file sharing and screen sharing — can also work between Macs with Back to My Mac enabled.
Image Credit: ehacatzin on Flickr