1st January 2009 No Comments Uncategorised admin

Nmap has been created by Fyodor.It is a major security tool.The Nmap includes features like port scanning,TCP Scan,UDP Scan,Syn Scan,OS Fingerprinting.

In this article we will cover some basic nmap features:


  1. First go to nmap.org and download nmap & install it.
  2. Then go to command prompt & type nmap.
  3. This will show you basic nmap help.


Type nmap our own machine) and press enter
The results are



Now lets focus on ports which are open

111/TCP Open rpcbind

631/tcp Open ipp


Now lets do a UDP scan.

nmap -sU
This will test for UDP scan.

Since UDP is connectionless protocol and so the packets may be lost during transaction. The state of ports reported by nmap in a UDP scan is either open/filtered.
If the packet sent doesnt return then packet may be filtered by the destination or the port may be closed in the case of the UDP Scan.
In nmap you can specify IP Address as a parameter instead of specifying host name directly.
 To look for IP Address from the host name follow these steps.
Open command prompt
Type nslookup <host name>
Eg. Nslookup www.abc.com

Lets assume that the address is somewhat
Now type nmap
The result would be same.


Let us take another example.

nmap –vv
 -vv stands for very verbose(It gives detailed info about the target host)
and it does a more comprehensive scan.




Now lets do OS fingerprinting for localhost.(OS fingerprinting allows to detect the Operating System on the system)
Type nmap -O

This -O option is likely to tell which OS might be running on the remote system.

Hope you find this basic tutorial useful.



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