X11 Forwarding is a special case of TCP/IP port forwarding. X11 protocol is used by PC X server software and connection is established from the remote host to the local PC; the opposite of other client programs such as email or telnet. By using the X11 forwarding option, you do not have to configure complex port forwarding rules required to run X11 applications over a secure tunnel.

To use X11 forwarding service, you should configure both Xshell and the remote ssh server.

To enable X11 forwarding service in Xshell:

  1. Open the Sessions dialog box.
  2. Select a session to enable its X11 forwarding service.
  3. From the toolbar, click Properties.
  4. From Category, select Connection.
  5. For Protocol, select SSH.
  6. From Category, Select SSH, and then Tunneling.
  7. Select Forward X11 connections to.
  8. If Xmanager® is installed, select Xmanager. If you are using a different PC X server, select X DISPLAY, and then enter the appropriate X DISPLAY information.
  9. Click OK. Note: The X display location is the display name of the PC X server. For Xmanager, Xshell is able to find it automatically. For other PC X server programs, you need to configure it manually. In most cases, "localhost:0.0" will be fine. For more information on X11 forwarding feature, see SSH: Tunneling.

To enable X11 forwarding service in the OpenSSH server:

  1. Open the /etc/ssh/sshd_config file.
  2. Set the X11Forwarding option as following:

    X11Forwarding   yes

  3. Restart the SSH server.

To enable X11 forwarding service in the SSH server of SSH.COM:

  1. Open the /etc/ssh2/sshd2_config file.
  2. Set the AllowX11Forwarding option as following:

    AllowX11Forwarding   yes

  3. Restart the SSH server.