- Do I already have nMap installed?
The first step toward obtaining Nmap is to check whether you already have it. Many free operating system distributions (including most Linux and BSD systems) come with Nmap packages, although they may not be installed by default.
PHP Code
<?php
$ nmap --version
Nmap version 4.76 ( http://nmap.org )
- How do I install nMap?
Nmap.Org is the official source for downloading Nmap source code and binaries for Nmap and Zenmap. Source code is distributed in bzip2 and gzip compressed tar files, and binaries are available for Linux (RPM format), Windows (NSIS executable installer) and Mac OS X (.dmg disk image). Find all of this at http://nmap.org/download.html.
- What is nMap?
Nmap (Network Mapper) is a security scanner originally written by Gordon Lyon (also known by his pseudonym Fyodor Vaskovich) used to discover hosts and services on a computer network, thus creating a "map" of the network.
- Discover IP's in a subnet
This is one of the simplest uses of nmap. This command is commonly refereed to as a "ping scan", and tells nmap to send an icmp echo request, TCP SYN to port 443, TCP ACK to port 80 and icmp timestamp request to all hosts in the specified subnet. It can be done by
PHP Code
<?php
$ nmap -sP 192.168.0.0/24
Starting Nmap 5.21 ( http://nmap.org ) at 2013-02-24 09:37 MST
Nmap scan report for 192.168.0.1
Host is up (0.0010s latency).
Nmap scan report for 192.168.0.95
Host is up (0.0031s latency).
Nmap scan report for 192.168.0.110
Host is up (0.0018s latency).
- Discover the Operating System
With the -O option nmap will try to guess the targets operating system. This is accomplished by utilizing information that nmap is already getting through the TCP SYN port scan. This is usually a best guess but can actually be fairly accurate. It can be done by
PHP Code
<?php
$ nmap -O 192.168.0.164
Starting Nmap 5.21 ( http://nmap.org ) at 2013-02-24 09:49 MST
Nmap scan report for 192.168.0.164
Host is up (0.00032s latency).
Not shown: 996 closed ports
PORT STATE SERVICE
88/tcp open kerberos-sec
139/tcp open netbios-ssn
445/tcp open microsoft-ds
631/tcp open ipp
MAC Address: 00:00:00:00:00:00 (Unknown)
Device type: general purpose
Running: Windows 7
Network Distance: 1 hop
- Scan for open ports
This scan is the default scan for nmap and can take some time to generate. With this scan nmap will attempt a TCP SYN connection to 1000 of the most common ports as well as an icmp echo request to determine if a host is up. It can be done by executing the following command
PHP Code
<?php
$ nmap 192.168.0.0/24
Starting Nmap 5.21 ( http://nmap.org ) at 2013-02-24 09:23 MST
Nmap scan report for 192.168.0.1
Host is up (0.0043s latency).
Not shown: 998 closed ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https
- UDP Scan and TCP Syn
The TCP SYN and UDP scan will take a while to generate but is fairly unobtrusive and stealthy. This command will check about 2000 common tcp and udp ports to see if they are responding. When you use the -Pn flag this tells nmap to skip the ping scan and assume the host is up.
PHP Code
<?php
$ nmap -sS -sU -PN 192.168.0.164
Starting Nmap 5.21 ( http://nmap.org ) at 2013-02-24 13:25 MST
Nmap scan report for 192.168.0.164
Host is up (0.00029s latency).
Not shown: 1494 closed ports, 496 filtered ports
PORT STATE SERVICE
88/tcp open kerberos-sec
139/tcp open netbios-ssn
445/tcp open microsoft-ds
631/tcp open ipp
88/udp open|filtered kerberos-sec
123/udp open ntp
137/udp open netbios-ns
138/udp open|filtered netbios-dgm
631/udp open|filtered ipp
5353/udp open zeroconf
- Fast scan
This scan limits the scan to the most common 100 ports, if you simply want to know some potential hosts with ports open that shouldn't be this is a quick command to use.
PHP Code
<?php
$ nmap -T4 -F 192.168.0.164
Starting Nmap 6.01 ( http://nmap.org ) at 2013-02-24 12:49 MST
Nmap scan report for 192.168.0.164
Host is up (0.00047s latency).
Not shown: 96 closed ports
PORT STATE SERVICE
88/tcp open kerberos-sec
139/tcp open netbios-ssn
445/tcp open microsoft-ds
631/tcp open ipp
- In-depth scan
Unlike some of the earlier commands this command is very aggressive and very obtrusive. It will scan every-port and every service that the host you are scanning is running and executing. To execute the following command enter in this
PHP Code
<?php
$ nmap -T4 -A 192.168.0.0/24
Nmap scan report for 192.168.0.95
Host is up (0.00060s latency).
Not shown: 996 closed ports
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 5.9p1 Debian 5ubuntu1 (protocol 2.0)
| ssh-hostkey: 1024 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:6c (DSA)
|_2048 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:6c (RSA)
80/tcp open http nginx 1.1.19
|_http-title: 403 Forbidden
|_http-methods: No Allow or Public header in OPTIONS response (status code 405)
111/tcp open rpcbind
| rpcinfo:
| program version port/proto service
| 100000 2,3,4 111/tcp rpcbind
| 100000 2,3,4 111/udp rpcbind
| 100003 2,3,4 2049/tcp nfs
| 100003 2,3,4 2049/udp nfs
| 100005 1,2,3 46448/tcp mountd
| 100005 1,2,3 52408/udp mountd
| 100021 1,3,4 35394/udp nlockmgr
| 100021 1,3,4 57150/tcp nlockmgr
| 100024 1 49363/tcp status
| 100024 1 51515/udp status
| 100227 2,3 2049/tcp nfs_acl
|_ 100227 2,3 2049/udp nfs_acl
2049/tcp open nfs (nfs V2-4) 2-4 (rpc #100003)
Service Info: OS: Linux; CPE: cpe:/o:linux:kernel
- TCP connect scan
This command is similar to the TCP SYN scan however rather than sending a SYN packet and reviewing the headers it will ask the OS to establish a TCP connection to the 1000 common ports.
PHP Code
<?php
$ nmap -sT 192.168.0.164
Starting Nmap 5.21 ( http://nmap.org ) at 2013-02-24 12:48 MST
Nmap scan report for 192.168.0.164
Host is up (0.0014s latency).
Not shown: 964 closed ports, 32 filtered ports
PORT STATE SERVICE
88/tcp open kerberos-sec
139/tcp open netbios-ssn
445/tcp open microsoft-ds
631/tcp open ipp
- UDP scan and TCP SYN scan for all ports
This command will specify the full port range from 1 to 65535 nmap will scan to see if the host is listening on all available ports. You can use the port range specification on any scan that performs a port scan.
PHP Code
<?php
$ nmap -sT 192.168.0.164
Starting Nmap 5.21 ( http://nmap.org ) at 2013-02-24 12:48 MST
Nmap scan report for 192.168.0.164
Host is up (0.0014s latency).
Not shown: 964 closed ports, 32 filtered ports
PORT STATE SERVICE
88/tcp open kerberos-sec
139/tcp open netbios-ssn
445/tcp open microsoft-ds
631/tcp open ipp
- Verbose
By adding verbose to a majority of the commands above you get a better insight into what nmap is doing; for some scans verbosity will provide additional details that the report does not provide.
PHP Code
<?php
$ nmap -T4 -A -v 192.168.0.164
Starting Nmap 6.01 ( http://nmap.org ) at 2013-02-24 12:50 MST
NSE: Loaded 93 scripts for scanning.
NSE: Script Pre-scanning.
Initiating Ping Scan at 12:50
Scanning 192.168.0.164 [2 ports]
Completed Ping Scan at 12:50, 0.00s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 12:50
Completed Parallel DNS resolution of 1 host. at 12:50, 0.01s elapsed
Initiating Connect Scan at 12:50
Scanning 192.168.0.164 [1000 ports]
Discovered open port 139/tcp on 192.168.0.164
Discovered open port 445/tcp on 192.168.0.164
Discovered open port 88/tcp on 192.168.0.164
Discovered open port 631/tcp on 192.168.0.164
Completed Connect Scan at 12:50, 5.22s elapsed (1000 total ports)
Initiating Service scan at 12:50
Scanning 4 services on 192.168.0.164
Completed Service scan at 12:51, 11.00s elapsed (4 services on 1 host)
NSE: Script scanning 192.168.0.164.
Initiating NSE at 12:51
Completed NSE at 12:51, 12.11s elapsed
Nmap scan report for 192.168.0.164
Host is up (0.00026s latency).
Not shown: 996 closed ports
PORT STATE SERVICE VERSION
88/tcp open kerberos-sec Mac OS X kerberos-sec
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: WORKGROUP)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: WORKGROUP)
631/tcp open ipp CUPS 1.4
| http-methods: GET HEAD OPTIONS POST PUT
| Potentially risky methods: PUT
|_See http://nmap.org/nsedoc/scripts/http-methods.html
| http-robots.txt: 1 disallowed entry
|_/
Service Info:
- Ening
So that's how you download, install, and use nMap. This is not all the commands nMap is limited to, but the ones I find most useful for you guys to use. If you wish to learn more about nMap, check out nMaps wiki where they have every command possibly executable on their wiki page. If you have any questions or concerns regarding this tutorial, please feel free to leave them below or PM me regarding it.
