To use X11 port forwarding, include the ForwardX11 in
the client configuration file (SSH_CONFIG.), or use one of the following options
to the SSH command:
The +x option, which enables untrusted
X11 connections (default)
The +X option, which enables trusted X11
connections
The -x option, which disables X11 connections
When X11 port forwarding is enabled on both the SSH client and server,
you can use SSH to connect to an SSH server and invoke X11 client programs
there, while having them appear on your local display. You can also "chain"
port forwarding across multiple systems, even if the intermediate systems
are not running the X11 server. For example, from SYSTEM1 you can use SSH
to connect to SYSTEM2, and then from SYSTEM2 connect to SYSTEM3. An X11 client
application running on SYSTEM3 will be displayed securely on SYSTEM1.
X11 access to an OpenVMS X11 server requires enabling access to the
X11 client. On HP DECwindows Motif for OpenVMS Systems, this can be done through
the Style Manager/security option:
Add the appropriate values for node and user name, and the
value tcpip as the transport. Details of how to enable
access on other platforms may differ.
To direct output to the forwarded X11 server port, enter the
following command:
$ SET DISPLAY/CREATE/TRANSPORT=TCPIP/NODE=Xserver
For Xserver, specify the name of
the SSH server. To direct output to the local SSH server, enter the keyword
LOCAL. To verify that the settings are correct, enter the following commands:
$ SHOW DISPLAY
Device: WSA777: [user]
Node: sshclient.myplace.com
Transport: TCPIP
Server: 10
Screen: 0$ SHOW LOGICAL DECW$DISPLAY
For more details about
the SET DISPLAY command, see the OpenVMS DCL Dictionary.
To terminate the display, exit the X11 client application,
and log out of the SSH session, enter the following command:
