How to use nmap in centos

1. Make sure if you have nmap in your system. perhaps check your nmap version

          #nmap --version

 yet no nmap available to your system. you need to install

          #yum install nmap

         #nmap localhost

-v giving more detailed information about the open ports

-A enables OS detection and version

 #namp -A localhost

-p denotes port range

 #nmap -p 10-15 localhost