Configure screen sharing for remote assistance


Mac OS X provides screen sharing functionality based VNC and it can be used for remote assistance. This document describes the configuration necessary to enable someone – a colleague or a Service Desk technician – to ask your permission to see your screen and to be to control it remotely in parallel with you.

Enabling someone to ask to see your screen

Step 1 - enable Screen Sharing

To enable the Screen Sharing, open System Preferences and select Sharing. Tick the box for Screen Sharing so that the status becomes “On”. Then, click on the “Computer Settings” button on the right.



In the pop up window, tick the box for “Anyone may request permission to control screen”. Validate by clicking on “OK”.

Step 2 – communicate your hostname or IP address

Once Screen Sharing is on, you will need to communicate your hostname or IP address to the person that you want to share your screen with.

You can do that by reading the text starting with “vnc://” from the Sharing pane, or by checking your hostname – as registered in CERN network database – using the website at:

Step 3 – accept connection request

When someone tries to connect to your screen, the window “Share Screen Request” will show up. Click on “Share Screen” to accept the connection. Please note that the control of your Mac will be shared between you and the person who connects.


Connecting to someone else’s screen

In order to connect to someone’s screen, open Finder, select Go > Connect to Server and specify the Server address in the form “vnc://hostname”.


Connectivity and security considerations

Sharing your screen as described above will work only within the local network. It will not work between CERN and a Mac on a different network, for example at home.

Having Screen Sharing enabled can have an impact on the security of your Mac so it is recommended to disable it before you use your Mac on a network other than your work or home network, for example when travelling, in a conference, etc.