Remote Access with VNC: Difference between revisions

   tux > vncviewer thinkserver.freddythechick.uk::5901

'''Note: Display and Port Number'''

The actual display or port number you specify in the VNC client must be the same as the display or port number picked by the '''<code>vncserver</code>''' command on the target machine. See Section 4.4, "Persistent VNC Sessions" for further info.

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==Adding Remote Sessions==

Complete the fields that specify your newly added remote session profile. The most important are:

Select the ''Advanced'' tab to enter more specific settings.

'''Tip: Disable Encryption'''

If the communication between the client and remote server is not encrypted, active ''Disable encryption'', otherwise the connection fails.

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To start a remote session quickly without proper adding and saving connection details, use the drop-down box and text field at the top of the main window.

===Opening Saved Remote Sessions===

===Remote Sessions Window===

Remote sessions are opened in tabs of a separate window. Each tab hosts one session. The toolbar on the left of the window helps you manage the windows/sessions, such as toggle full-screen mode, resize the window to match the display size of the session, send specific keystrokes to the session, take screenshots of the session, or set the image quality.

==Editing, Copying and Deleting Saved Sessions==

   tux > remmina -c profie_name.remmina

Remmina's profile files are stored in the <code>.local/share/remmina/</code> directory in your home directory. To determine which profile file belongs to the session you want to open, run Remmina, click the session name in the main window, and read the path to the profile file in the window's status line at the bottom.

While Remmina is not running, you can rename the profile file to to a more reasonable file name, such as <code>sle15.remmina</code>. You can even copy the profile file to your custom directory and run it using the '''<code>remmina -c</code>''' command from there.

# In case not all needed packages are available yet, you need to approve the installation of missing packages.

'''Tip: Restart the Display Manager'''

YaST makes changes to the display manager settings. You need to log out of your current graphical session and restart the display manager for the changes to take effect.

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==Available Configurations==

   tux > sudo systemctl reload xvnc.socket

'''Important: Firewall and VNC Ports'''

When activating Remote Administration as described in Procedure 4.1, "Enabling One-time VNC Sessions", the ports <code>5801</code> and <code>5901</code> are opened in the firewall. If the network interface serving the VNC sessions is protected by a firewall, you need to manually open the respective ports when activating additional ports for VNC sessions. See Book ''"Security Guide", Chapter 15 "Masquerading and Firewalls"'' for instructions.

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A persistent session can be accessed from multiple clients simultaneously. This is ideal for demonstration purposes where one client has full access and all other clients have view-only access. Another use case are trainings where the trainer might need access to the trainee's desktop.

'''Tip: Connecting to a Persistent VNC Session'''

To connect to a persistent VNC session, a VNC viewer must be installed. Refer to Section 4.1, "The '''<code>vncviewer</code>''' Client" for more details.

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The password(s) you are providing here are also used for future sessions started by the same user. They can be changed with the '''<code>vncpasswd</code>''' command.

'''Important: Security Considerations'''

Make sure to use strong passwords of significant length (eight or more characters. Do no share these passwords.

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   WINDOWMANAGER=icewm vncserver -geometry 1024x768

'''Note: One Configuration for Each User'''

Persistent VNC sessions are configured in a single per-user configuration. Multiple sessions started by the same user will all use the same start-up and password files.

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# In case not all needed packages are available yet, you need to approve the installation of missing packages.

'''Tip: Restart the Display Manager'''

YaST makes changes to the display manager settings. You need to log out of your current graphical session and restart the display manager for the changes to take effect.

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===Configuring Persistent VNC Sessions===

After you enable the VNC session management as described in Procedure 4.3, "Enabling Persistent VNC Sessions", you can normally connect to the remote session with your favourite VNC viewer, such as '''<code>vncviewer</code>''' or Remmina. You will be presented with login screen. After you log in, the 'VNC' icon will appear in the system tray of your desktop environment. Click the icon to open the ''VNC Session'' window. If it does not appear or if your desktop environment does not support icons in the system tray, run '''<code>vncmanager-controller</code>''' manually.

There are several settings which influence the VNC session behaviour:

===Joining Persistent VNC Sessions===

After you set up a persistent VNC session as described in Section 4.4.2.1, "Configuring Persistent VNC Sessions", you can join it with your VNC viewer. After the your VNC client connects to the server, you will be prompted to choose whether you want to create a new session, or join the existing one:

After you click the name of the existing session, you may be asked for login credentials, depending on the persistent session settings.

TLS encryption with certificate. If you use a self-signed certificate, you will be asked to verify it on the first connection. On subsequent connections you will be warned only if the certificate changed. So you are protected against everything except man-in-the-middle on the first connection (similar to typical SSH usage). If you use a certificate signed by a certificate authority matching the machine name, then you get full security (similar to typical HTTPS usage).

'''Tip: Path to Certificate and Key'''

With X509 based encryption, you need to specify the path to the X509 certificate and the key with <code>-X509Cert</code> and <code>-X509Key</code> options.

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