How to find currently active systems in your network using nmap.

This post will help you to get the IP address of all the host (systems/computers)
which are currently active in you network. For example if you are using a network 192.168.1.0/24 network ie may be in your institution you are having an ip address of 192.168.1.25. Then you will be able to know all the IP address currently active in the range 192.168.1.xxx. This can be done using nmap which is used as a hack tool to analyze remote systems.

Steps:
+++++

1) If you are not having nmap already installed on your system you may have to install
   it first.
  
   a) if you are using ubuntu or debian systems

   -------------------------
   sudo apt-get install nmap
   -------------------------
 
   b) if you are using fedora or centos
  
   ----------------
   yum install nmap
   ---------------
2) Once this is done you can always execute the following command and
   find out currently turned on systems in your network.

  
   -----------------------------------------------------------------
   nmap -sP 192.168.1.0/24
   -----------------------------------------------------------------

   Example:
   ________________________________________________________________
   rzm@rasim:~$ nmap -sP 192.168.1.0/24

   Starting Nmap 5.21 ( http://nmap.org ) at 2013-07-26 06:56 IST
   Nmap scan report for 192.168.1.1
   Host is up (0.0056s latency).
   Nmap scan report for 192.168.1.2
   Host is up (0.021s latency).
   Nmap scan report for 192.168.1.3
   Host is up (0.00050s latency).
   Nmap done: 256 IP addresses (3 hosts up) scanned in 3.50 seconds
   ________________________________________________________________
  
   The above example shows 3 host which are active in my network.






Hope you have enjoyed the post

rzm