Ubuntu Screen Sharing

Setup Vino server from a terminal

Inform the system which graphic display to interact with

1	export DISPLAY=:0

Turn on Vino

1	gsettings set org.gnome.Vino enabled true

Turn off Vino encryption

1	gsettings set org.gnome.Vino require-encryption false

If not the following error will pop up：

Unable to connect to VNC Server using your chosen security setting. Either upgrade VNC Server to a more recent version from RealVNC or select a weaker level of encryption.

Turn off prompt alert

1	gsettings set org.gnome.Vino prompt-enabled false

Allow linked sources

To only allow local connections, open a terminal and run the command:

1	gsettings set org.gnome.Vino network-interface lo

To allow connections from anywhere, open a terminal and run the command:

1	gsettings reset org.gnome.Vino network-interface

Reboot the system so that the settings take effect

1	sudo reboot

VNC server’s graphical configuration tool (Optional)

Change Vino settings in the GUI.

Enable sharing
Ubuntu uses Vino as screen sharing VNC Server, Here is how to set it up:

Open settings panel: Setting -> Sharing -> Screen Sharing

Vino self control panel: vino-preferences

It set the quality of the graphical interface.

Connecting using VNC Viewer

Start vino server

if not start vino server you can execute the following steps:

Method 1: systemctl --user start vino-server
Method 2: /usr/lib/vino/vino-server

Install vnc client

Mac install vnc-viewer: brew cask install vnc-viewer
Linux client: gvncviewer and remmina
Windows client: vnc-viewer

Get your IP address

ifconfig

Connect

Put link information on the client：10.0.1.199:5900

If screen size is too small after connecting, you can set an appropriate width and height through this: xrandr --fb 1280x1024, More info: xrandr

Use a reverse ssh tunnel port to connect vnc

1	ssh -i ~/.ssh/id_rsa -fCNR 5922:localhost:5900 username@host

This is meaning forward port 5900 to remote host 5922

option -f to detach ssh process from the tty
option -C to allow compress data
option -N to not execute any command over ssh
option -R to reverse ssh tunnel

If set remote host sshd config /etc/ssh/sshd_config with GatewayPorts clientspecified, You can use follow command to expose remote port to 0.0.0.0

1	ssh -i ~/.ssh/id_rsa -fCNR :5922:localhost:5900 username@host

otherwise use socat to do port forward:

1	socat tcp-listen:5923,fork,reuseaddr tcp:127.0.0.1:5922

then you can connect host:5923 with vnc viewer

Other error

If can not start vino-server by this error:

No protocol specified
Unable to init server: Could not connect: Connection refused
Cannot open display:
Run 'vino-server --help' to see a full list of available command-line options

Just restart ubuntu display manager:

1	sudo systemctl restart display-manager