VHA Innovations Program Future Technology Laboratory. Linux Workstation Remote Desktop Connection Manual

Transcription

1 VHA Innovations Program Future Technology Laboratory Linux Workstation Remote Desktop Connection Manual

2 Table of Contents VHA Innovations Program... 1 Purpose... 3 Prerequisites... 3 Windows Users... 3 Mac OS X Users... 3 How secure connections are made to Linux Workstation... 4 Creating the Secure Tunnel from Windows... 5 Open Putty... 5 Configure SSH Session... 5 Configure X11 or X Display Location... 5 Configure Tunnel Port Forwarding... 6 Establish Tunnel... 7 Accept Certificate (first time connecting)... 7 Session Logon... 8 Connecting to Desktop... 9 Desktop Established Reconnecting to Desktop Creating the Secure Tunnel on Mac OS X Connect to Desktop on Mac OS X Resetting VNC Sessions... 15

3 Purpose The purpose of this guide is to provide instruction on how to connect to the remote desktop of a Linux workstation in a secure manner. Prerequisites Before a connection can be made to a Linux workstation you will need two utilities. The utilities are a terminal application that can create secure shell (SSH) connections and a virtual network computing (VNC) viewer application for the remote desktop connection. Windows Users For windows users you can download the following programs free of charge: SSH Client (Putty) Vist: or VNC Viewer (TightVNC) Download and install these programs using the instructions found on their respective websites. Mac OS X Users If you are using an Apple computer, everything is already installed as part of the OS. Terminal App This is the application that can make SSH connections. If can be found through the Finder here: Applications -> Utilities -> Terminal Screen Sharing The Screen Sharing utility that Apple has is a VNC viewer. To access the screen sharing utility directly you can use Finder to traverse: Macintosh HD -> System -> Library -> Core Services -> Screen Sharing *You can drag Screen Sharing it to your Dock to keep it handy

4 How secure connections are made to Linux Workstation To connect to a Linux workstation there is a two-step process. First, it is necessary to create a secure tunnel to the Linux workstation using a SSH client and then connect to the desktop with the VNC viewer. The way this is done is by forwarding the port used for the desktop through the tunnel and then connecting to the forwarded port on your local machine. The port to forward depends on what port is set up for a user account to access the VNC server. The typical ports are in the range of When a Linux Workstation is requested with VNC access, the server name, IP address, username, and VNC port are provided individually to users.

5 Creating the Secure Tunnel from Windows Open Putty To open Putty, you can either use the run command and type putty and press <enter> or use the Start Menu to find it under Applications and click to execute the program. When Putty opens, it will be at the PuTTY Configuration settings page under the Session Category as shown below. Configure SSH Session Type the name of the server you will be connecting to in the Host Name (or IP Address) field. Port 22 will already be selected. Configure X11 or X Display Location Next, click on SSH - > X11 in the pane on the left side of the Putty window. Enter the X display location. The location will be always be localhost with the display number being the port assigned to your username for a VNC connection. The display number is the last digit of the VNC port.

6 For example, if your instructions for connecting show something like: The X display location would be localhost:3 joe@someserver.vaftl.us:5906 The X display location would be localhost:6 Configure Tunnel Port Forwarding Click on the SSH - > Tunnel Category below X11 Type your servername and VNC port in the Destination field. If your settings show: bob@someserver.vaftl.us:5906 Your Destination would be:

7 someserver.vaftl.us:5906 After you have added your destination, type 7070 for the Source port. Click the Add button next to Source port Establish Tunnel Click the Open button to create your tunnel to the server. Accept Certificate (first time connecting) If it is the first time connecting from a particular machine, there will be a prompt to accept the servers certificate. Click Yes.

8 Session Logon To finish establishing the tunnel, provide your server username and password.

9 Once logged in do not close this window. If the terminal session closes, the connection to the desktop will be halted as well. You can minimize this window. Connecting to Desktop Open TightVNC and enter the Remote Host as: :7070 Click the Connect button. If all the settings have been correct, there will be a prompt for a Password. Enter the supplied password to connect to the desktop.

10 Desktop Established The desktop window will now appear.

11 Reconnecting to Desktop When you reconnect, it will be necessary to provide the password to your linux desktop.

12 Creating the Secure Tunnel on Mac OS X Using Terminal App - Built into the Mac OS X Operating System, Either click the Spotlight (Magnifying Glass icon) in the upper right corner of the screen and type Terminal and hit <enter> or Look in Finder under Applications -> Utilities If the connection information is given as: username@someserver.vaftl.us:5902 You would connect typing this command: ssh L 7070: :5902 username@someserver.vaftl.us hit <enter> If you are prompted to accept the security certificate hit y and enter. Otherwise, type the supplied password and hit <enter>. Do not close the Terminal Application while using the remote desktop session. If you close the Terminal application you will have to reconnect.

13 Connect to Desktop on Mac OS X Next, open the Screen Sharing utility It is located through Finder at: Macintosh HD -> System -> Library -> Core Services -> Screen Sharing *You can drag it to your Dock to keep it handy Type localhost:7070 and click Connect Enter the supplied password and click Connect

14 The desktop should now be visible for use.

15 Resetting VNC Sessions If the vnc session becomes unusable, it can be reset without affecting other users of the server. If you connect to port 5904, you would use the following command in your SSH session (Putty or Terminal App) to kill the malfunctioning vnc session: Kill your hosed VNC session vncserver - kill :4 Killing Xvnc process ID Restart your VNC session vncserver :4 If you are using port 5902 you would use :2, 5905 would be :5, etc