Unfortunately, I still do NOT get any X-Windows program (e.g., xlcock) to come back. It there some other setting somewhere that sets $DISPLAY properly? In this particular case, I can force the setting export DISPLAY=localhost:10.0, which then returns correctly after running echo $DISPLAY. Then I try to verify the $DISPLAY variable, but get no output (it's not set). I do NOT receive any failed X11 attempts in ssh. This is a STDOUT error and not an error from the ssh -vvv. When I try to run xclock it fails with an error of ' Can't open display: localhost:10.0'. When I ssh in using -X (and add verbosity for troubleshooting -vvv), I successfully connect. Xauth is installed on the server, and after successfully connecting over SSH I do get a MAGIC-COOKIE in ~/.Xauthority. On the server-side I have the following sshd_config settings:

I have tried all of the settings suggested in this almost identical question, but to no avail. I am running CentOS/RHEL 6 and having the same issues as described in the referenced question below.

Mobaxterm x11 forwarding