Tim, thank you very much. I was able to go one more step forward. this is still refer to the Oracle 11gR2 RAC install on Linux with NFS.
At the 8th image of Grid Infrastructure installation, I only got "eth0 192.168.2.0 public", and never get 'eth1 192.168.0.0 private'.
I did edit eth0 when installed Linux, and the only place have eth1 is in /etc/hosts file, also I have exact entries in my /etc/hosts file as in your article for 11gR2 RAC install on Linux with NFS.
Please help to have this eth1 showup.
It is so much fun to work on this installation as it required so much Linux admin skills.
I am just an Oracle DBA, try to learn Linux here.