information provided for listener is currently in use by another software - Virtualbox

I know this is a common problem that I have come across many time, while installing oracle software on Virtual machine  >>  Linux (Guest OS). I thought of sharing this info as this might help others to ..

Problem / Error :

I was trying to install oracle software on virtual box. I keep getting this error information provided for listener is currently in use by another software.

(or) 

Port you have provided xxxx (1523) is being used by another program.

Solution : 

Step 1 : Make sure you login as Root user.

Step 2 : make sure your valid ip address  in   >>    /etc/hosts

Step 3 : Make sure no other program is using listener port   >> netstat -ntap | grep 1521

In my case initially it had wrong ip address in the /etc/hosts  file.