I'm trying to force an xterm to open from a remote host, D, over an SSH connection between boxes B and C, to display on my windows PC, A.

Box A, the windows PC has a windows-based Xserver (EOD). I connect to box B and run Gnome. From box B, I run ssh -Y C xterm -ls. So then I get an xterm from box C running through the window manager on Box B, displaying on Box A.

Box D is the difficult part. It cannot route to Boxes B or A, and it doesn't have SSH installed. I can open an xterm to its local display, and I can open an xterm pointed back to a X11 tunneler on Box C, xmond, which then gets displayed back to box A. (I connect to Box D from box C using RSH and Telnet)

I'd like to get this xterm from box D running through the SSH tunnel between boxes B and C. Instead, when I run xterm -display C:10, I get this error: "X11 connection rejected because of wrong authentication." Ultimately, I'd like to run a proprietary X11 application over this tunnel, just using xterm to get started.

Has anyone been able to use an SSH tunnel between two boxes to route X11 from a third?

your method of ssh from a to b, run the window manager, then run an Xterm on box b, and ssh with X forwarding into box C seems the most logical, but yes, you could look into iptables to forward say, port 23 from box a to port 22 on box c via box b

Did you perform any user changes using su while you jumped from one host to the next?
If so check that your .Xauthority file got the right contents.

---------- Post added 09-10-12 at 09:33 PM ----------

You may want as well to have a look here: http://brakertech.com/xlib-putty-x11...col-attempted/

not using su, but box D doesn't have SSH, so I rsh as root to that box.

From desktop A: <EOD> to box B, start gnome
From box B: ssh -Y C xterm -ls
From box C: rsh D -l root (or telnet)
From box D: xeyes -display D:10 (pointing to my ssh tunnel)