dbca inside dmz server

doing the regular display setup do not work when you are inside dmz server .

so I had to do this .

keep your exceed open. ssh using my loginid first with X11 tunnelling on .

as user ou1234>

find the display by env . it should be something like
DISPLAY=localhost:11.0

then you should see a .Xauthority file in user ou1234's home directory .

do a chmod on this file . better put this inside user ou1234's .profile

$ cat .profile
chmod 660 .Xauthority

and then su as the oracle user

su - oracle

and then export DISPLAY to the display as you found inside ou1234's env variable
As oracle user
$ export DISPLAY=localhost:11.0
$ export XAUTHORITY=/home/nrusip01/.Xauthority
$ xclock

now you are ready to do any gui actvity.