Nmap (Network Mapper)

What is Nmap?

Nmap is a port scanning tool developed by Fyodor Vaskovich. It is an open port scanning tool.It determine what hosts are available on the network, services offered by host, which operating systems that hosts are running etc.

Nmap installation

In Ubuntu,nmap is installed using the syntax

 

sudo apt-get install nmap

 

Nmap Port Scanning

Port can be scanned by providing the ip address of the host(Here I am using localhost address.)This gives the port and services opened by the target machine.

jothis@jothis:~$  nmap  127.0.0.1

Starting Nmap 5.21 ( http://nmap.org ) at 2013-01-25 17:50 IST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00019s latency).
Not shown: 997 closed ports
PORT     STATE SERVICE
53/tcp   open  domain
631/tcp  open  ipp
3306/tcp open  mysql

Nmap done: 1 IP address (1 host up) scanned in 0.05 seconds

OS fingerprint detection using Nmap

 

For OS finger printing (finding the operating system of remote host) is given by the syntax.The bold characters show the os running in the target machine.

jothis@jothis:~$ sudo nmap -O 127.0.0.1
[sudo] password for jothis:

Starting Nmap 5.21 ( http://nmap.org ) at 2013-01-25 17:58 IST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000079s latency).
Not shown: 997 closed ports
PORT     STATE SERVICE
53/tcp   open  domain
631/tcp  open  ipp
3306/tcp open  mysql
No exact OS matches for host (If you know what OS is running on it, see http://nmap.org/submit/ ).
TCP/IP fingerprint:
OS:SCAN(V=5.21%D=1/25%OT=53%CT=1%CU=36083%PV=N%DS=0%DC=L%G=Y%TM=51027A88%P=
OS:i686-pc-linux-gnu)SEQ(SP=106%GCD=1%ISR=10B%TI=Z%CI=Z%II=I%TS=8)OPS(O1=M4
OS:00CST11NW4%O2=M400CST11NW4%O3=M400CNNT11NW4%O4=M400CST11NW4%O5=M400CST11
OS:NW4%O6=M400CST11)WIN(W1=8000%W2=8000%W3=8000%W4=8000%W5=8000%W6=8000)ECN
OS:(R=Y%DF=Y%T=40%W=8018%O=M400CNNSNW4%CC=Y%Q=)T1(R=Y%DF=Y%T=40%S=O%A=S+%F=
OS:AS%RD=0%Q=)T2(R=N)T3(R=Y%DF=Y%T=40%W=8000%S=O%A=S+%F=AS%O=M400CST11NW4%R
OS:D=0%Q=)T4(R=Y%DF=Y%T=40%W=0%S=A%A=Z%F=R%O=%RD=0%Q=)T5(R=Y%DF=Y%T=40%W=0%
OS:S=Z%A=S+%F=AR%O=%RD=0%Q=)T6(R=Y%DF=Y%T=40%W=0%S=A%A=Z%F=R%O=%RD=0%Q=)T7(
OS:R=Y%DF=Y%T=40%W=0%S=Z%A=S+%F=AR%O=%RD=0%Q=)U1(R=Y%DF=N%T=40%IPL=164%UN=0
OS:%RIPL=G%RID=G%RIPCK=G%RUCK=G%RUD=G)IE(R=Y%DFI=N%T=40%CD=S)

Network Distance: 0 hops

OS detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 11.48 seconds