mwenyenia07 -4 Light Poster

I installed oracle 11g R2 on centos 6.4 and it was successful. However, If I am not on LAN(Local Area Network), then it does not start properly i.e the TNS fails.

During installation, There is no where I specified IP Address;yet, it can only work when I plug network cable. Please help me make it work on my laptop even when am not connected.