Information Gathering

Information gathering means collecting as much information as available regarding target networking. Nmap is best tool for collecting information . User can also execute their own script via “Nmap script engine”. Nmap script engine is one of the most powerful feature of nmap.list of nmap command are as below:

1.Nmap  192.168.0.1         (Show the open port of 192.168.0.1)
2.Nmap  192.168.0.1/24   (Show the open port from 192.168.0.1 to 192.168.0.24)
3.Nmap  192.168.0.*         (show the all open port)
4.Nmap –O 192.168.0.1     (check the opeating system of specified internal IP)
5.Nmap  -sP 192.168.0.1/24  (ping the ranged IP address) 
6.Nmap  -T5 192.168.0.1/24  (Quick scan)
7.Nmap  --top-ports 20 192.168.0.1/24  (scan the top 20 ports of ranged network)
8.Nmap  -sT –p80 192.168.0.*   (scan the tcp onnection of port 80)  (-sT=tcp scan,p80 =port 80 )
9.Nmap  -v 192.168.0.1  (for scanning top 1000 port of IP)
10.Nmap  -f  192.168.0.* --exclude 192.168.0.2  (scan the top 100 ports of ranged IP exclude 192.168.0.2

Full form of  command

1. -sT     TCP scan

2. -sS      SYN scanning

3. -sF      FIN scan

4. -sN      Null scan

5. -sX      Tree scan

6. -sP      ping scan

7. -sU      UDP scan

8.  -O       Operating system

9. -sI       Idle scanning

10. -sA     ACK scan

11. -F       fast scan

12. man  nmap -manual page of nmap

Information also collected with the help of zenmap which is graphical version of nmap provide the same feature and accessibility as available in namp.

Note: nmap is important tool with lots of feature  user don’t have to learn the namp command as most of the command starting with the first alphatebate of name. (eg –sT=TCP)