Set up a computer running VNC software for Remote Desktop
VNC access is determined by the VNC software. To access a computer running VNC, you only need to know the IP address or fully qualified domain name and the password designated in the VNC software. The VNC password doesn’t necessarily correspond to any other password on the system.
Set up a non-macOS client running VNC software
You can set up a non-macOS client to be viewed with Remote Desktop.
Install the VNC Server software and assign a VNC password on the client computer.
Make sure the client’s firewall has the VNC port open (TCP 5900).
For more detailed instructions on steps 1–2, see the documentation that came with the client operating system, VNC software, and firewall software.
Make sure “Encrypt all network data” isn’t selected in the Security pane of Remote Desktop preferences.
If you encrypt network data, you won’t be able to control the VNC client, because Remote Desktop can’t open the necessary SSH tunnel to that computer. When you try to control a computer running VNC software, you see a warning that the keystrokes aren’t encrypted.
Add the computer to the All Computers list in Remote Desktop using the client’s IP address.
Enter the client computer’s VNC password in the Remote Desktop authentication dialog.
Configure a client to be controlled by non-Apple VNC software
You can configure a Remote Desktop client to be controlled with non–Apple VNC software. Allowing non–Apple VNC software access to a Remote Desktop client is less secure than using Remote Desktop to control the client. The VNC protocol implemented in non–Apple VNC software may not encrypt keystrokes sent over the network, so sensitive information can be intercepted. Also, the non–Apple VNC software expects the password to be stored in a cryptographically unsecured form and location. Granting VNC access to control a screen is the most powerful feature in Remote Desktop, and provides nearly unrestricted access.
WARNING: Don’t select a VNC password that’s the same as the password of any local user on the client computer or of the Remote Desktop administrator.
On the client computer, choose Apple menu > System Preferences, click Sharing, then select Remote Management in the list at the left.
Click Computer Settings, then select “VNC viewers may control screen with password.”
Enter a VNC password, then click OK.
Change the VNC port on an existing computer
After you add a computer running VNC software to a computer list (or when you’re first adding it), you can set a custom port for VNC communication, and you can designate a display to control.
In Remote Desktop , select a computer list in the sidebar of the main window, select a computer running VNC software, then choose File > Get Info.
Click Edit, edit the Screen Sharing Port field, then click Done.
Designate a custom VNC port when adding a computer
You can pick a custom VNC port on which to view clients. Custom VNC ports are used for Network Address Translation (NAT) implementations, firewall settings, or viewing multiple displays.
In Remote Desktop , choose File > Add by Address, then enter the following:
The IP address or fully qualified domain name of the client computer
The user name and password
If the client computer uses NAT, click the Advanced Options triangle.
Enter the public ports that are mapped to the client in the Remote Management Port field and the Screen Sharing Port field, then click Add.