Set up a Q4OS Remote Desktop Server

Prerequisites

• Q4OS system with administrative access
• Network connectivity between client and server
• Firewall configuration access
• Understanding of basic networking concepts

VNC Server Setup

Installing VNC Server

Install TightVNC server package:

sudo apt update
sudo apt install tightvncserver

Initial VNC Configuration

1. Start VNC server for the first time to create configuration files:

   vncserver :1

2. Set a VNC password when prompted (6-8 characters)
3. Choose whether to set a view-only password
4. Stop the VNC server:

   vncserver -kill :1

Configuring VNC Startup Script

Edit the VNC startup script to use Trinity desktop:

nano ~/.vnc/xstartup

Replace the contents with:

#!/bin/bash
xrdb $HOME/.Xresources
starttrinity &

Make the script executable:

chmod +x ~/.vnc/xstartup

Starting VNC Server

Start VNC server with specific resolution:

vncserver :1 -geometry 1024x768 -depth 24

Creating VNC Service

Create a systemd service for automatic startup:

sudo nano /etc/systemd/system/vncserver@.service

Add the following content:

[Unit]
Description=Start TightVNC server at startup
After=syslog.target network.target

[Service]
Type=forking
User=your-username
PAMName=login
PIDFile=/home/your-username/.vnc/%H:%i.pid
ExecStartPre=-/usr/bin/vncserver -kill :%i > /dev/null 2>&1
ExecStart=/usr/bin/vncserver -depth 24 -geometry 1024x768 :%i
ExecStop=/usr/bin/vncserver -kill :%i

[Install]
WantedBy=multi-user.target

Enable and start the service:

sudo systemctl daemon-reload
sudo systemctl enable vncserver@1.service
sudo systemctl start vncserver@1.service

RDP Server Setup

Installing XRDP

Install XRDP for RDP protocol support:

sudo apt update
sudo apt install xrdp

Configuring XRDP

Configure XRDP to use Trinity desktop:

echo "starttrinity" > ~/.xsession

Start and enable XRDP service:

sudo systemctl start xrdp
sudo systemctl enable xrdp

XRDP Security Configuration

Configure SSL certificate for encryption:

sudo openssl req -x509 -newkey rsa:2048 -nodes -keyout /etc/xrdp/key.pem -out /etc/xrdp/cert.pem -days 365

Edit XRDP configuration:

sudo nano /etc/xrdp/xrdp.ini

Update the SSL settings:

security_layer=tls
certificate=/etc/xrdp/cert.pem
key_file=/etc/xrdp/key.pem

Restart XRDP service:

sudo systemctl restart xrdp

SSH Server Setup

Installing SSH Server

Install OpenSSH server:

sudo apt update
sudo apt install openssh-server

SSH Configuration

Edit SSH configuration for security:

sudo nano /etc/ssh/sshd_config

Recommended security settings:

Port 22
Protocol 2
PermitRootLogin no
PasswordAuthentication yes
PubkeyAuthentication yes
X11Forwarding yes
X11DisplayOffset 10

Restart SSH service:

sudo systemctl restart ssh

SSH Key Authentication (Recommended)

Generate SSH key pair on client:

ssh-keygen -t rsa -b 4096

Copy public key to server:

ssh-copy-id username@server-ip

X11 Forwarding for GUI Applications

Connect with X11 forwarding enabled:

ssh -X username@server-ip

Launch GUI applications remotely:

firefox &
kate &

NoMachine NX Setup

Installing NoMachine

Download NoMachine from the official website:

wget https://download.nomachine.com/download/7.10/Linux/nomachine_7.10.1_1_amd64.deb
sudo dpkg -i nomachine_7.10.1_1_amd64.deb

NoMachine Configuration

NoMachine works out of the box with minimal configuration. The service starts automatically after installation.

Check service status:

sudo systemctl status nxserver

NoMachine Client Connection

Download NoMachine client on remote computer and connect using:

• Server address: Q4OS machine IP
• Port: 4000 (default)
• Authentication: System username/password

Firewall Configuration

UFW Firewall Rules

Configure UFW firewall to allow remote desktop connections:

Enable UFW:

sudo ufw enable

Allow VNC connections:

sudo ufw allow 5901/tcp  # VNC display :1
sudo ufw allow 5902/tcp  # VNC display :2

Allow RDP connections:

sudo ufw allow 3389/tcp

Allow SSH connections:

sudo ufw allow 22/tcp

Allow NoMachine connections:

sudo ufw allow 4000/tcp

Network-Specific Rules

Restrict access to specific networks for security:

sudo ufw allow from 192.168.1.0/24 to any port 5901
sudo ufw allow from 192.168.1.0/24 to any port 3389

Client Connections

VNC Clients

• TightVNC Viewer: Free cross-platform VNC client
• RealVNC Viewer: Professional VNC client
• Remmina: Linux remote desktop client
• Built-in clients: Many operating systems include VNC viewers

VNC connection format:

server-ip:5901  # For display :1
server-ip:5902  # For display :2

RDP Clients

• Windows: Built-in Remote Desktop Connection
• Linux: Remmina, Vinagre, FreeRDP
• macOS: Microsoft Remote Desktop
• Mobile: RD Client apps

RDP connection settings:

• Computer: server-ip:3389
• Username: Q4OS username
• Password: Q4OS password

Security Considerations

Authentication

• Use strong passwords for all accounts
• Enable SSH key authentication when possible
• Consider two-factor authentication
• Disable unused user accounts

Network Security

• Use VPN for connections over internet
• Restrict access to specific IP ranges
• Change default ports when possible
• Enable logging and monitor access

Encryption

• Enable TLS/SSL encryption for RDP
• Use SSH tunneling for VNC connections
• Consider VNC over SSH for added security

VNC over SSH Tunnel

Create secure VNC connection through SSH tunnel:

ssh -L 5901:localhost:5901 username@server-ip

Then connect VNC client to localhost:5901

Troubleshooting

Common VNC Issues

• Gray screen: Check xstartup script configuration
• Connection refused: Verify VNC server is running and firewall allows connections
• Authentication failure: Reset VNC password with vncpasswd

Common RDP Issues

• Black screen: Check .xsession file and Trinity desktop installation
• Certificate errors: Verify SSL certificate configuration
• Connection drops: Check network stability and XRDP logs

Log Files

Check these log files for troubleshooting:

• VNC: ~/.vnc/*.log
• XRDP: /var/log/xrdp.log
• SSH: /var/log/auth.log
• System: /var/log/syslog

Performance Optimization

VNC Performance

• Use lower color depth (16-bit instead of 24-bit)
• Reduce screen resolution for slower connections
• Enable compression in VNC client
• Disable desktop effects and animations

RDP Performance

• Adjust connection speed settings in RDP client
• Disable desktop wallpaper and animations
• Use lower color quality for slow connections
• Enable bitmap caching

Network Optimization

• Use wired connection when possible
• Ensure adequate bandwidth
• Configure QoS for remote desktop traffic
• Monitor network latency