How to Enable Screen Sharing via VNC/RDP on FreeBSD Operating System

Screen sharing is essential for remote desktop access, troubleshooting, and collaboration. On FreeBSD, you can set up screen sharing using VNC (Virtual Network Computing) or RDP (Remote Desktop Protocol). This guide walks you through installing, configuring, and securing VNC and RDP for remote access on a FreeBSD system.

Prerequisites

Before proceeding, ensure you have:

• A FreeBSD system with root or sudo privileges
• A working internet connection
• Installed Xorg and a desktop environment (e.g., XFCE, KDE, or GNOME) if using a graphical interface

Enabling Screen Sharing via VNC

Step 1: Install a VNC Server

Several VNC servers are available for FreeBSD, including TightVNC, TigerVNC, and RealVNC. TigerVNC is commonly used due to its performance and reliability.

To install TigerVNC, run:

pkg install tigervnc-server

Alternatively, you can install TightVNC:

pkg install tightvnc

Step 2: Configure the VNC Server

After installation, create a VNC password for authentication:

vncpasswd

This command will prompt you to set a password, which clients will use to connect.

Next, create a startup script for the VNC server. Edit or create the ~/.vnc/xstartup file:

echo "#!/bin/sh" > ~/.vnc/xstartup
echo "exec startxfce4" >> ~/.vnc/xstartup
chmod +x ~/.vnc/xstartup

Modify startxfce4 to match your installed desktop environment (e.g., startkde for KDE or gnome-session for GNOME).

Step 3: Start the VNC Server

Start the VNC server on a specific display (e.g., :1):

vncserver :1

You can stop it using:

vncserver -kill :1

Step 4: Configure the VNC Service for Automatic Startup

Create a system service for the VNC server. Edit /etc/rc.conf and add:

vnc_enable="YES"
vncserver_args="-geometry 1920x1080 -depth 24"

Then, create a startup script in /usr/local/etc/rc.d/vncserver:

#!/bin/sh
# PROVIDE: vncserver
# REQUIRE: LOGIN
# KEYWORD: shutdown

. /etc/rc.subr

name="vncserver"
rcvar="vncserver_enable"
command="/usr/local/bin/vncserver"
command_args=":1 -geometry 1920x1080 -depth 24"
pidfile="$HOME/.vnc/%h:1.pid"

load_rc_config $name
run_rc_command "$1"

Set executable permissions:

chmod +x /usr/local/etc/rc.d/vncserver
service vncserver start

Step 5: Secure the VNC Connection

VNC does not encrypt connections by default. To enhance security, tunnel the connection through SSH:

ssh -L 5901:localhost:5901 -N -f -l username remote_host

Then, connect to localhost:1 using a VNC client.

Enabling Screen Sharing via RDP

Step 1: Install an RDP Server

Xrdp is a popular RDP server for Unix-like systems. Install it with:

pkg install xrdp

Step 2: Configure Xrdp

Edit the configuration file /usr/local/etc/xrdp/xrdp.ini if necessary. The default settings usually work fine.

Enable and start the service:

echo 'xrdp_enable="YES"' >> /etc/rc.conf
service xrdp start

Step 3: Open RDP Ports in the Firewall

If using pf (Packet Filter), add the following rule to /etc/pf.conf:

pass in on $ext_if proto tcp from any to any port 3389

Reload the firewall:

service pf reload

Step 4: Connect Using an RDP Client

On a Windows or Linux machine, use an RDP client such as Remmina, FreeRDP, or Windows Remote Desktop to connect to the FreeBSD machine using its IP address.

Conclusion

By following these steps, you can enable screen sharing on FreeBSD using either VNC or RDP. VNC is best for graphical environments, while RDP is more suited for Windows interoperability. Always secure remote access with SSH tunneling, firewall rules, or VPN to protect your system from unauthorized access.