Hi,
Hello,
I am from the OpenVMS Support Team. We do have X11 Forwarding working in both OpenSSH V8.9-1i01 as well as OpenSSH V8.9-1J. I use it every day in my job here at VSI, so I know it works as it should.
Pre-Reqs:
OpenVMS X86 V9.2-2 w/Update 2. You will want to have the OpenVMS DECWindows Update V1.8-2 installed.
OpenVMS Alpha, you will need to have V1.7-0E or later installed. In addition, you will need to install the RTLv9 update kit when it becomes available. We found that there are some POSIX memory allocation routines that are causing issues in RTLv6 and later that were causing some issues. This is fixed in the forthcoming RTLv9 release.
OpenVMS IA64, you will want to have DECWindows V1.7-0E or later installed, and like the Alpha Architecture, you will also need to have RTLv9 installed for everything to work as you expect.
What doesn't work, is X11 Forwarding in this case acting as a proxy to allow you to bounce a Decwindows app from a OpenVMS system, to a PC, to yet another PC. In other words, using a Xwindows Client to function as a X11 Proxy to allow a DECWindows application to be displayed from OpenVMS to a PC or Linux X11 Server, and then sending that application to yet another PC or Linux X11 Xserver.
Simple Example:
OpenVMS (DECW$CLOCK) --> Windows 11, XMING w/Putty --> Windows 11, Xming w/Putty
How to remotely display X11 application on an Ubuntu 20 desktop
On the client Ubuntu Desktop system
An Ubuntu 24.04 desktop, is by default not supporting displaying remote X11 based applications as Ubuntu X Windows system is based on "Wayland" instead of the one from X.org. You can easily check this with the command:
$ echo $XDG_SESSION_TYPE
wayland
When you see as output "wayland" instead of "x11" then you know we have some work to perform to allow remote X11 application to be able to pop-up on our Ubuntu desktop.
To modify this please edit the
/etc/gdm3/custom.conf file and uncomment the
"WaylandEnable" line as follows and restart the system:
# Uncomment the line below to force the login screen to use Xorg:
WaylandEnable=false
Next:
To accept "x11" applications add the following to your personal Secure Shell config file ($HOME/.ssh/config) as global variables:
ForwardAgent yes
ForwardX11 yes
ForwardX11Trusted yes
On the remote system where the x11 application runs:
To allow
X11 forwarding on the remote system we also need to make sure that in the
/etc/ssh/ssh_config file (not your local Ubuntu desktop system) we uncomment or add the following lines:
# ForwardAgent no
ForwardX11 yes
ForwardX11Trusted yes
Furthermore, also edit the
/etc/ssh/sshd_config file and define the following settings:
X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost no
The
X11UseLocalhost no setting is required to avoid the error message X11 forwarding request failed on channel 0 [2].
And finally, restart the Secure Shell daemon (sshd) with the command :
sudo systemctl restart sshd
The Remote X11 test:
On your Ubuntu desktop, bring up a terminal window, and execute the command: "xhost +" (without the quotes).
Again, from your Ubuntu desktop (via a terminal window) login on the remote server from where you want to launch a x11 application and get it visible on your Ubuntu desktop. Therefore, use the following command:
ssh
username@fully.qual.domain.name
Now, you can launch any available x11 application and have that application's GUI interface displayed on your Ubuntu desktop, e.g. /usr/bin/xclock -or- /usr/bin/xterm etc...
For SYSTEMS using MS-Windows 10 or MS-Windows 11 and using Xvnc, Xming, ReflectionsX, eXceed, MobaXterm.
On Your OpenVMS System:
1) Set your default directory to be SSH$ROOT:[ETC]
2) Edit your SSH_CONFIG.
3) Just below the line that has "# ForwardAgent no" add the following two lines:
ForwardX11 yes
ForwardX11Trusted yes
4) Save the file and exit the editor.
5) Next, edit the SSHD_CONFIG. file.
6) Locate the line that reads: "#GatewayPorts no", add or uncomment the three lines shown below:
X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost no
7) Save the file and exit your editor.
8) This will require a restart of OpenSSH on all versions of OpenVMS that are using OpenSSH V8.9-1i01 or later.
NOTE: Doing this will drop
all OpenSSH connections. Do not do this from an SSH login on OpenVMS either.
Instead, use "Telnet" to do this or use a connection through the Remote Console Login.
9) After restarting OpenSSH on the OpenVMS system you will need to start your PC-Xserver. Then initiate a SSH session via putty or your favorite terminal emulator that supports SSH connections.
If on Putty, then make sure you have X11 Forwarding enabled.
Category: CONNECTIONS --> SSH -->X11 --> ENABLE X11 FORWARDING AND MIT-MAGIC-COOKIE-1
You should be able to leave X-DISPLAY-LOCATION and X AUTHORITY FILE FOR LOCAL DISPLAY options BLANK.
These are the exact steps that I've been able to use to get DECWindows Apps (including an entire CDE New Desktop session) to display on my local PC, From Boston MA, to Houston, Tx.
Rick Retterer