Here is a quick way to work using Remote Desktop from macOS (Golden Gate) to Ubuntu (24.04 LTS, X11).

Ubuntu 24.04 removed the long term supported VNC protocol, and only RDP connection are now allowed via System > Remote Desktop. We could use Windows App (formerly MS Remote Desktop, available on the App Store), but if we want to stick with Apple Screen Sharing utility, we can install x11vnc on the remote machine:

$ sudo apt install x11vnc
$ x11vnc -storepasswd

This, of course, assumes you are running on x11 and not Wayland (check that with echo $XDG_SESSION_TYPE). ¹ Now, let the app run in the background using the following instruction:

$ x11vnc -usepw -display :0

If that doesn’t work, we are better off leaving x11vnc guessing the host screen for us:

$ x11vnc -usepw -auth guess

If that still doesn’t work, e.g. we’re getting a « denying additional client » error message from Ubuntu, it’s probably because we need to allow multiple connections to the server:

$ x11vnc -usepw -auth guess -shared -forever

Now you be able to connect to your Ubuntu workstation using Spotlight (vnc://:5900) or the Screen Sharing app directly. Note that once you connected using Spotlight, the distant machine will be available in the list of available connections in the Screen Sharing app.

If you want to enable this permanently, you can simply write a service that will start at login

# /etc/systemd/system/x11vnc.service
[Unit]
Description=Serveur VNC
After=multi-user.target

[Service]
Type=simple
User=<username>
ExecStart=/usr/bin/x11vnc -usepw -auth guess -forever -shared
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target

Personally, I prefer to launch the VNC server upon connecting via ssh, for security reasons. On top of that, you may add this Linux machine to your Tailscale network and connect using its tailnet IP instead of your work network.