TightVNC
TightVNC is a fast and lightweight remote control package. This choice will ensure that our VNC connection will be smooth and stable even on slower internet connections. It encrypts VNC passwords sent over the net (DES-encrypted challenge-response scheme and the password is limited by 8 characters), but the rest of the traffic is sent in the clear and are a security risk. Recommended is using TightVNC with ssh (and that defeats our purpose of only using it when ssh fails)
Installation
Install the Xfce desktop environment on the server:
# apt-get install xfce4 xfce4-goodies
Install the vnc server:
# apt-get install tightvncserver
Create a new user to access the server.
# useradd vncuser
Add the user to the sudo group:
# usermod -aG sudo vncuser
As the vncuser, set up a secure password and create the initial configuration files:
vncuser@localhost $ vncserver
You will require a password to access your desktops.
Password:
Verify:
Creating default startup script /home/vncuser/.vnc/xstartup
Starting applications specified in /home/vncuser/.vnc/xstartup
Log file is /home/vncuser/.vnc/localhost.localdomain:1.log
Enter and verify a password to access the server remotely. It must be between six and eight characters long. More than 8 characters will be truncated automatically. The process then creates the necessary default configuration files and connection information for the server.
Configuration
Default for the service is on port 5901 (display port :1). Stop the service:
$ vncserver -kill :1
Make a backup of the xstartup file:
$ mv ~/.vnc/xstartup ~/.vnc/xstartup.old
Create a new xstartup file and open it (empty file):
$ vi ~/.vnc/xstartup
To have VNC read the server user’s .Xresources file and launch Xfce (in the background), append:
#!/bin/bash
xrdb $HOME/.Xresources
startxfce4 &
Write and quit file, and (as root) make it executable.
# chmod +x ~/.vnc/xstartup
Restart VNC:
$ vncserver
Firewall
Open ports in the firewall for inbound communication.
Control
For starting, stopping, and restarting the service, create a new (empty) systemd unit file /etc/systemd/system/vncserver@.service
# vi /etc/systemd/system/vncserver@.service
The @ symbol will allow for passing an argument (the VNC display port). Append:
[Unit]
Description=Start TightVNC server at startup
After=syslog.target network.target
[Service]
Type=forking
User=vncuser
Group=vncuser
WorkingDirectory=/home/vncuser
PIDFile=/home/vncuser/.vnc/%H:%i.pid
ExecStartPre=-/usr/bin/vncserver -kill :%i > /dev/null 2>&1
ExecStart=/usr/bin/vncserver -depth 24 -geometry 1280x800 :%i
ExecStop=/usr/bin/vncserver -kill :%i
[Install]
WantedBy=multi-user.target
Reload systemd manager configuration
# systemctl daemon-reload
Enable the unit file
# systemctl enable vncserver@1.service
Kill the vncserver
$ vncserver -kill :1
And start it as any other systemd service.
$ sudo systemctl start vncserver@1
Verify
$ sudo systemctl status vncserver@1
Clients
Windows: TightVNC, RealVNC, or UltraVNC.
MacOS: Apple Remote or RealVNC.
Linux: vinagre, krdc, RealVNC, or TightVNC.