the dreaded X11 forwarding request failed on channel 0 so you’ve tried: ssh  dev2user@dev2server.somedomain.com and getting the following error on screen when trying to run something that requires x11 forwarding (like xclock or some type of installer perhaps?):

try this:

1. login to your server (as root or some type of super user):

   ssh root@dev2server.somedomain.com

2. install xauth

   yum install xauth

3. edit /etc/ssh/sshd_config file

   vi /etc/ssh/sshd_config

   set the following two options:

   X11Forwarding yes X11UseLocalhost no

   save and close the file

4. logout and login again as your desired user ssh  dev2user@dev2server.somedomain.com

   xclock