IBM Support

How to forward an X11 client through a Jump Host back to a PC with an X Emulator

How To


Summary

Basic steps to forward an X11 client through a Jump host back to a PC with an X Emulator

Environment

ASSUMPTIONS:

This document uses the following names for the systems:

remoteDisplay: This is the PC or Desktop where an Xserver is running
jumpHost: The AIX System used to connect through the firewall to 'aixClient'
aixClient: The AIX System where the X11 clients run, to display to 'remoteDisplay'

2) The following is enabled in /etc/ssh/sshd_config on 'jumpHost' and aixClient':

X11Forwarding yes Default is no
X11UseLocalhost yes Default is yes - If you modify this setting, the following instructions must be modified and tested to reflect that configuration.

Steps

======================================
On 'remoteDisplay'
======================================

1) Start the Xserver (e.g. Xming, Cygwin, etc).

2) Invoke the PC terminal (For example, PuTTY)  connection to 'jumpHost' with SSH X11 forwarding enabled.

  Note - The command-line equivalent is:  ssh -X user@ 'jumpHost'

======================================
In NEW SSH session on 'jumpHost'
======================================

3) Confirm SSH X11 forwarding was enabled.

% echo $DISPLAY

This command should return 'localhost:n'

4) Initiate a new forwarded ssh session with 'aixClient'.

% ssh -Y user@'aixClient'

======================================
In NEW SSH session on
'aixClient'
======================================

5) Confirm SSH X11 forwarding was enabled.

% echo $DISPLAY

This command should return 'localhost:n'

6) Invoke an X11 client.

% xclock

This command displays the xclock on the PC Xserver display, from:
 'aixClient'--> to 'jumpHost' --> to 'remoteDisplay'

Additional Information

SUPPORT

If you require more assistance, use the following step-by-step instructions to contact IBM to open a case for software with an active and valid support contract.  

1. Document (or collect screen captures of) all symptoms, errors, and messages related to your issue.

2. Capture any logs or data relevant to the situation.

3. Contact IBM to open a case:

   -For electronic support, see the IBM Support Community:
     https://www.ibm.com/mysupport
   -If you require telephone support, see the web page:
      https://www.ibm.com/planetwide/

4. Provide a clear, concise description of the issue.

 - For guidance, see: Working with IBM AIX Support: Describing the problem.

5. If the system is accessible, collect a system snap, and upload all of the details and data for your case.

 - For guidance, see: Working with IBM AIX Support: Collecting snap data

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"X11;SSH","Platform":[{"code":"PF002","label":"AIX"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}}]

Document Information

Modified date:
16 July 2021

UID

ibm10719873