Remote access usually refers to one of three things. First, you might want to access the files on a Mac at home or in an office from someplace else. Second, you might want to take control of that Mac’s desktop as if you were sat in front of it (known as screen sharing). Lastly, if you’re technically inclined you might want to remotely access the Mac’s command-line.
Your Mac comes with everything you need and it’s literally just a few clicks away.
How to use Back to My Mac
Part of Apple’s iCloud service, Back to My Mac makes it magically appear as if you’re on the same network as your home or office Mac – even if it (or you) are located on the other side of the world. It’s easy to use and by far the best choice for remote access of all kinds although it’s Mac-to-Mac only – Windows and Linux users need not apply.
The Internet router that the home or office Mac connects to will need to have either Universal Plug and Play (UPnP) or NAT Port Mapping (NAT-PMP) activated. Some ISPs enable this out of the box. Others don’t. Often the best solution is to call or email your ISP’s support people, or hit Google.
Activating UPnP or NAT-PMP isn’t vital but without it connections will be significantly slower. When screen sharing in particular this can be frustrating.
Both Macs will need to be logged into the same iCloud account, and have Back to My Mac activated within the iCloud pane of System Preferences. On the Mac in the home or office that you want to access remotely you’ll also need to have enabled File Sharing and/or Screen Sharing in the Sharing pane of System Preferences. You may also need to enable Wake For Network Access in the Energy Saver pane, but if you use iCloud’s Find My Mac then this will already be activated.
Notably, there’s no need to configure any of the above on the Mac you’re using to access the remote computer. This simply needs to have Back to My Mac enabled. Upon opening Finder you’ll then find the remote computer listed under the Shared heading at the left of the window.
Selecting it will automatically connect as a guest for file sharing, but clicking the Connect As button at the top right of the Finder window will let you enter your login details to get full access (and remember you need to type the login details of the REMOTE Mac, not the one you’re currently using!).
To initiate a screen sharing session, again click the Share Screen button and enter the remote Mac’s username and password.
By keeping Back to My Mac enabled, the remote Mac will automatically show-up in Finder at all times. If the remote Mac is connected to an AirPort Express, or use a Time Capsule, or if there’s an Apple TV on the network, then it can go into sleep mode and will be woken on demand when you connect. If none of the above hardware is present the remote Mac should be left always running. An app like Caffeine, activated before you leave the office/home, will stop the Mac entering sleep mode.
How to remote access a Mac using port forwarding
If you’re technically inclined you can ignore Back to My Mac in order to create a DIY solution. The key benefit is that Windows and Linux computers can remotely access the Mac too.
The file and screen sharing technologies used by Yosemite (SMB3 and VNC) and are secure enough for use across the Internet, although you should ensure your username and password are non-obvious.
All you need do is enable port forwarding to the Mac for incoming SMB and VNC services on your Internet router. How this is done varies depending on the router and again you may need to Google. Some routers are compatible with dynamic DNS services, which means you can use the same hostname without worrying about a changing IP address.
Once port forwarding is setup, to open a file sharing connection to the remote Mac from a Windows computer, open the Start menu and in the Search field type two backslashes, followed by the Internet address or dynamic DNS hostname of the router (e.g. \\keirmac.dyndns.com). With a Linux desktop environment, choose to connect to a server and enter smb:// followed by the address (e.g. smb://keirmac.dyndns.com). For screen sharing, use a VNC client on Windows or Linux and simply type the address when prompted.
Enable SSH to connect to a Mac command line
Macs come with Secure Shell (SSH) built-in to enable you to connect remotely to the command-line. Enabling SSH is as simple as putting a tick alongside Remote Login within the Sharing pane of System Preferences on the home or office Mac. Again, to access the remote Mac across the Internet you’ll need to enable SSH port forwarding on the router.
To connect, open a Terminal window (it’s in the Utilities folder within Applications in Finder), then type ssh followed by the username for the remote Mac, followed by @ and then the address. An example might be ssh [email protected] When connecting for the first time you’ll be prompted to accept the remote Mac’s key file, and then prompted to enter the remote Mac’s password.
To logout, tap Ctrl+D and then close the Terminal window. The above instructions work on Linux computers too, while on a Windows computer you can connect via PuTTY.
Activating Remote Login also switches-on Secure File Transfer (SFTP), which provides another method of remotely accessing files that virtually any computer can use. Unfortunately, while Macs can share files via SFTP, you can’t use Finder to connect to an SFTP file share. Instead you must use a client app like Filezilla, for which there’s also a version for Windows and Linux. From a Mac or Linux command-line you can also use the sftp command (e.g. sftp [email protected]).
Also worth investigating is SSH tunnelling. This is outside the boundaries of this guide but Googling will reveal instructions. SSH Tunnel Manager makes setup easy on the remote Mac.
Use Chrome Remote Desktop to connect to a Mac
If you use the Chrome web browser then the Chrome Remote Desktop extension allows you to screen share your remote Mac’s desktop with other Macs, or Windows, Linux and Chromebook computers. Google has provided a comprehensive getting started guide.