Screens Connect is the easiest way to make a computer available for connections from outside its local network, but under certain circumstances, Screens Connect isn't a viable option. In such cases, it's still possible to connect to a computer from across the Internet.
Note: Make sure you enable Screen Sharing on your Mac before you go through these instructions. Refer to Screens' help documentation to learn more.
Step 1: Update your public IP address automatically
Your public IP address will change from time to time. To make sure that Screens can find your computer when connecting locally, you will need to subscribe to a service that will monitor IP address changes.
For this example, we chose a free service called No-IP, which is not associated in any way with Edovia. There are many similar services available on the web and they all have a similar setup procedure.
Create a No-IP account and host
- Go to http://www.no-ip.com/.
- Select “No-IP Free”.
- Sign Up for the service.
- Once your No-IP account has been created and validated, go to https://www.no-ip.com/login/ to log in.
- You'll land on your No-IP page.
- Select “Add a Host”.
- Type a Hostname.
- Make sure “DNS Host (A)” is selected.
- Do not change the IP address. It is your current public IP address.
- Click on “Create Host”.
Install the Host Updater
Many routers will let you do this easily, without having to install any additional software on your Mac. Consult this page to see if your router supports the No-IP service.
If your router doesn't support the service, follow these instructions:
- Go to http://www.no-ip.com/downloads.php.
- Select the download for your OS (Mac, Windows or Linux).
- Download the latest version of the app.
- Scroll down the Download page in order to get the installation instructions.
Step 2: Make your Mac's local IP address static
Like your public IP address, your local IP address may change from time to time. We need to make sure it stays the same.
- Open System Preferences → Network.
- Select “Using DHCP with manual address”.
- Select a static IP that will not conflict with anything else on the network. It’s best to pick a number far out of the normal range of assigned IP’s, in the example below we chose 10.0.1.245 because most of the machines on this network stop at 10.0.1.150. Check your router's IP address to know which range to use.
- Click on the “Apply” button in the lower right corner.
- Your IP will now manually set to the static address you provided, you will briefly disconnect from the network while this occurs.
- Close Network settings and System Preferences.
Step 3: Port-Forwarding
As your network requires a public IP address, you will also need to create public ports that will redirect to your new static IP address and the private port used by Screen Sharing (normally 5900 unless you have changed it).
For the sake of this example, we'll use an Airport Extreme. If you have a different router, we suggest that your consult the excellent Port Forward website. Select your router brand and model, and then select “VNC” on the next page.
- Open “Airport Utility”.
- Select your router if it's not already selected.
- Click “Manual Setup” and enter your administrative password.
- Click the “Advanced” tab, then the “Port Mapping” tab.
- Click the + button to add a new port mapping.
- A settings window will appear.
- Select “Apple Remote Desktop” in the Service list.
- In the “Private IP Address” field, enter the static IP address you've created in Step 2.
- Click “Continue”, then “Done”.
- Click “Update” to apply the changes on your router.
Step 4: Setting up Screens
- Open Screens and create or edit a screen like you would normally do.
- In the Address field, type your No-IP host. In our case, it's “lucsmacbookair.zapto.org”.
- Set the Port field to 5900 or whatever port number you used in Step 3.
- Select the correct Operating System, Authentication method and credentials.
- Select the screen to initiate a connection.