The X11 plugin (part of the gateway) allows Member State users who have an X11 server running on their workstation to log into their shell account and start X11 applications directly on ECMWF systems. First, users must check that their DISPLAY environment variable is properly set up on their workstation:
-> echo $DISPLAY hostname:0.0
The content of this variable is the name of the display to which X11 applications will connect (usually the name of the user workstation). If users have a server access control program for X, they must add the gateway hostname to their host list allowed to make connections to their X11 server, e.g., assuming that the Member State ECaccess gateway (see Ecaccess concepts) runs on the server "ecaccess.meteo.ms", with the "xhost" command
-> xhost +ecaccess.meteo.ms ecaccess.meteo.ms being added to access control list
The MS gateway is then authorized to open connections to their X11 server. Note that the "xhost" command is only required for telnet, not for ssh. After these preliminary settings you should be able to request an X11 proxy via your telnet or SSH connection. Each subsequent X11 application started from this xterm window (including new xterm) will make connections to your X11 server.
11.1 Starting xterm within a SSH session
By connecting to "ecaccess.ecmwf.int" with the SSH plugin described in The SSH server, after having been validated with your security token, you will first have to select the system at ECMWF to access. Note that you may have to use "ssh -X" to open the X11 tunnel.