Configure VNC (Virtual Network Computing) for Remote Desktop in Linux

 

Configure VNC (Virtual Network Computing) for Remote Desktop in RHEL 8 

 

In CentOS 8 / RHEL 8, GNOME is the default desktop environment. if you don’t have it in your system, install it using the following command:

[root@RHEL8 ~]# dnf groupinstall "workstation"

Or

[root@RHEL8 ~]# dnf groupinstall "Server with GUI"

Once the above packages are installed successfully then run the following command to enable the graphical mode

[root@RHEL8 ~]# systemctl set-default graphical

 

 

Now reboot the system so that we get GNOME login screen.

[root@RHEL8 ~]# reboot

 

 

Once the system is rebooted successfully uncomment the line “WaylandEnable=false” from the file “/etc/gdm/custom.conf” so that remote desktop session request via vnc is handled by xorg of GNOME desktop in place of wayland display manager.

 

 

VNC server will not work properly if SElinux is enabled on your system, as of now work around is to disable it using following commands,

[root@RHEL8 ~]# setenforce 0

[root@RHEL8 ~]# sed -i 's/enforcing/disabled/g' /etc/selinux/config

 

 

Step 2) Install VNC Server (tigervnc-server)

Next we’ll install the VNC Server, there are lot of VNC Servers available, and for installation purposes, we’ll be installing TigerVNC Server. It is one of the most popular VNC Server and a high-performance and platform-independent VNC that allows users to interact with remote machines easily.

Now install TigerVNC Server using the following command:

[root@RHEL8 ~]# dnf install tigervnc-server tigervnc-server-module -y

 

 

Step 3) Set VNC Password for Local User

Let’s assume we want ‘Vishnubane’ user to use VNC for remote desktop session, then switch to the user and set its password using vncpasswd command,

[root@RHEL8 ~]# su - Vishnubane

[Vishnubane@linuxtechi ~]$ vncpasswd

Password:

Verify:

Would you like to enter a view-only password (y/n)? n

A view-only password is not used

[Vishnubane@linuxtechi ~]$

[Vishnubane@linuxtechi ~]$ exit

logout

[root@RHEL8 ~]#

 

 

Step 4) Setup VNC Server Configuration File

Next step is to configure VNC Server Configuration file. Create a file “/etc/systemd/system/vncserver@.service” with the following content so that tigervnc-server’s service started for above local user “Vishnubane”.

[root@RHEL8 ~]# vim /etc/systemd/system/vncserver@.service

[Unit]

Description=Remote Desktop VNC Service

After=syslog.target network.target

 

 

[Service]

Type=forking

WorkingDirectory=/home/Vishnubane

User=Vishnubane

Group=Vishnubane

 

 

ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i  /dev/null 2 &1 || :'

ExecStart=/usr/bin/vncserver -autokill %i

ExecStop=/usr/bin/vncserver -kill %i

 

 

[Install]

WantedBy=multi-user.target

 

 

Save and exit the file,

 

 

Note: Replace the user name in above file which suits to your setup.

By default, VNC server listen on tcp port 5900+n, where n is the display number, if the display number is “1” then VNC server will listen its request on TCP port 5901.

 

 

Step 5) Start VNC Service and allow port in firewall

I am using display number as 1, so use the following commands to start and enable vnc service on display number “1”,

[root@RHEL8 ~]# systemctl daemon-reload

[root@RHEL8 ~]# systemctl start  vncserver@:1.service

[root@RHEL8 ~]# systemctl enable  vncserver@:1.service

Created symlink /etc/systemd/system/multi-user.target.wants/vncserver@:1.service → /etc/systemd/system/vncserver@.service.

[root@RHEL8 ~]#

Use below netstat or ss command to verify whether VNC server start listening its request on 5901,

[root@RHEL8 ~]# netstat -tunlp | grep 5901

tcp    0      0 0.0.0.0:5901            0.0.0.0:*           LISTEN  8169/Xvnc

tcp6   0      0 :::5901                 :::*                LISTEN  8169/Xvnc

[root@RHEL8 ~]# ss -tunlp | grep -i 5901

tcp   LISTEN  0   5                0.0.0.0:5901       0.0.0.0:*      users:(("Xvnc",pid=8169,fd=6))               

tcp   LISTEN  0   5                   [::]:5901          [::]:*      users:(("Xvnc",pid=8169,fd=7))               

[root@RHEL8 ~]#

Use below systemctl command to verify the status of VNC server,

[root@RHEL8 ~]# systemctl status vncserver@:1.service

 

Above command’s output confirms that VNC is started successfully on port tcp port 5901. Use the following command allow VNC Server port “5901” in os firewall,

[root@RHEL8 ~]# firewall-cmd --permanent --add-port=5901/tcp

success

[root@RHEL8 ~]# firewall-cmd --reload

success

[root@RHEL8 ~]#

 

 

Step 6) Connect to Remote Desktop Session

Now we are all set to see if the remote desktop connection is working. To access the remote desktop, Start the VNC Viewer from your Windows  / Linux workstation and enter your VNC server IP Address and Port Number and then hit enter

 

Next, it will ask for your VNC password. Enter the password that you have created earlier for your local user and click OK to continue

 

Now you can see the remote desktop.

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