29 Practical Examples of Nmap Commands for Linux System/Network Administrators

Read Time: 16 minsCategories Linux Commands 37 Comments

The Nmap aka Network Mapper is an open source and a very versatile tool for Linux system/network administrators. Nmap is used for exploring networks, perform security scans, network audit and finding open ports on remote machine. It scans for Live hosts, Operating systems, packet filters and open ports running on remote hosts.

Nmap Commands
Nmap Commands and Examples

I’ll be covering most of NMAP usage in two different parts and this is the first part of nmap serious. Here in this setup, I have used two servers without firewall to test the working of the Nmap command.

  1. 192.168.0.100 – server1.tecmint.com
  2. 192.168.0.101 – server2.tecmint.com
Nmap command usage
# nmap [Scan Type(s)] [Options] {target specification}

How to Install NMAP in Linux

Most of the today’s Linux distributions like Red Hat, CentOS, Fedoro, Debian and Ubuntu have included Nmap in their default package management repositories called Yum and APT. The both tools are used to install and manage software packages and updates. To install Nmap on distribution specific use the following command.

# yum install nmap		[on Red Hat based systems]

$ sudo apt-get install nmap	[on Debian based systems]

Once you’ve install latest nmap application, you can follow the example instructions provided in this article.

1. Scan a System with Hostname and IP Address

The Nmap tool offers various methods to scan a system. In this example, I am performing a scan using hostname as server2.tecmint.com to find out all open ports, services and MAC address on the system.

Scan using Hostname
[root@server1 ~]# nmap server2.tecmint.com

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 15:42 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.415 seconds
You have new mail in /var/spool/mail/root
Scan using IP Address
[root@server1 ~]# nmap 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 11:04 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
958/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.465 seconds
You have new mail in /var/spool/mail/root

2. Scan using “-v” option

You can see that the below command with “-v” option is giving more detailed information about the remote machine.

[root@server1 ~]# nmap -v server2.tecmint.com

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 15:43 EST
Initiating ARP Ping Scan against 192.168.0.101 [1 port] at 15:43
The ARP Ping Scan took 0.01s to scan 1 total hosts.
Initiating SYN Stealth Scan against server2.tecmint.com (192.168.0.101) [1680 ports] at 15:43
Discovered open port 22/tcp on 192.168.0.101
Discovered open port 80/tcp on 192.168.0.101
Discovered open port 8888/tcp on 192.168.0.101
Discovered open port 111/tcp on 192.168.0.101
Discovered open port 3306/tcp on 192.168.0.101
Discovered open port 957/tcp on 192.168.0.101
The SYN Stealth Scan took 0.30s to scan 1680 total ports.
Host server2.tecmint.com (192.168.0.101) appears to be up ... good.
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.485 seconds
               Raw packets sent: 1681 (73.962KB) | Rcvd: 1681 (77.322KB)

Scan Multiple Hosts

You can scan multiple hosts by simply writing their IP addresses or hostnames with Nmap.

[root@server1 ~]# nmap 192.168.0.101 192.168.0.102 192.168.0.103

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:06 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)
Nmap finished: 3 IP addresses (1 host up) scanned in 0.580 seconds

4. Scan a whole Subnet

You can scan a whole subnet or IP range with Nmap by providing * wildcard with it.

[root@server1 ~]# nmap 192.168.0.*

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:11 EST
Interesting ports on server1.tecmint.com (192.168.0.100):
Not shown: 1677 closed ports
PORT    STATE SERVICE
22/tcp  open  ssh
111/tcp open  rpcbind
851/tcp open  unknown

Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 256 IP addresses (2 hosts up) scanned in 5.550 seconds
You have new mail in /var/spool/mail/root

On above output you can see that nmap scanned a whole subnet and gave the information about those hosts which are Up in the Network.

5. Scan Multiple Servers using last octet of IP address

You can perform scans on multiple IP address by simple specifying last octet of IP address. For example, here I performing a scan on IP addresses 192.168.0.101, 192.168.0.102 and 192.168.0.103.

[root@server1 ~]# nmap 192.168.0.101,102,103

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:09 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 3 IP addresses (1 host up) scanned in 0.552 seconds
You have new mail in /var/spool/mail/root

6. Scan list of Hosts from a File

If you have more hosts to scan and all host details are written in a file , you can directly ask nmap to read that file and perform scans. Let’s see how to do that.

Create a text file called “nmaptest.txt” and define all the IP addresses or hostname of the server that you want to do a scan.

[root@server1 ~]# cat > nmaptest.txt

localhost
server2.tecmint.com
192.168.0.101

Next, run the following command with “iL” option with nmap command to scan all listed IP address in the file.

[root@server1 ~]# nmap -iL nmaptest.txt

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 10:58 EST
Interesting ports on localhost.localdomain (127.0.0.1):
Not shown: 1675 closed ports
PORT    STATE SERVICE
22/tcp  open  ssh
25/tcp  open  smtp
111/tcp open  rpcbind
631/tcp open  ipp
857/tcp open  unknown

Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
958/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
958/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 3 IP addresses (3 hosts up) scanned in 2.047 seconds

7. Scan an IP Address Range

You can specify an IP range while performing scan with Nmap.

[root@server1 ~]# nmap 192.168.0.101-110

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:09 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 10 IP addresses (1 host up) scanned in 0.542 seconds

8. Scan Network Excluding Remote Hosts

You can exclude some hosts while performing a full network scan or when you are scanning with wildcards with “–exclude” option.

[root@server1 ~]# nmap 192.168.0.* --exclude 192.168.0.100

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:16 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 255 IP addresses (1 host up) scanned in 5.313 seconds
You have new mail in /var/spool/mail/root

9. Scan OS information and Traceroute

With Nmap, you can detect which OS and version is running on the remote host. To enable OS & version detection, script scanning and traceroute, we can use “-A” option with NMAP.

[root@server1 ~]# nmap -A 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:25 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE VERSION
22/tcp   open  ssh     OpenSSH 4.3 (protocol 2.0)
80/tcp   open  http    Apache httpd 2.2.3 ((CentOS))
111/tcp  open  rpcbind  2 (rpc #100000)
957/tcp  open  status   1 (rpc #100024)
3306/tcp open  mysql   MySQL (unauthorized)
8888/tcp open  http    lighttpd 1.4.32
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)
No exact OS matches for host (If you know what OS is running on it, see http://www.insecure.org/cgi-bin/nmap-submit.cgi).
TCP/IP fingerprint:
SInfo(V=4.11%P=i686-redhat-linux-gnu%D=11/11%Tm=52814B66%O=22%C=1%M=080027)
TSeq(Class=TR%IPID=Z%TS=1000HZ)
T1(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW)
T2(Resp=N)
T3(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW)
T4(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=)
T5(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
T6(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=)
T7(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
PU(Resp=Y%DF=N%TOS=C0%IPLEN=164%RIPTL=148%RID=E%RIPCK=E%UCK=E%ULEN=134%DAT=E)

Uptime 0.169 days (since Mon Nov 11 12:22:15 2013)

Nmap finished: 1 IP address (1 host up) scanned in 22.271 seconds
You have new mail in /var/spool/mail/root

In above Output, you can see that nmap is came up with TCP/IP fingerprint of the OS running on remote hosts and being more specific about the port and services running on the remote hosts.

10. Enable OS Detection with Nmap

Use the option “-O” and “-osscan-guess” also helps to discover OS information.

[root@server1 ~]# nmap -O server2.tecmint.com

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:40 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)
No exact OS matches for host (If you know what OS is running on it, see http://www.insecure.org/cgi-bin/nmap-submit.cgi).
TCP/IP fingerprint:
SInfo(V=4.11%P=i686-redhat-linux-gnu%D=11/11%Tm=52815CF4%O=22%C=1%M=080027)
TSeq(Class=TR%IPID=Z%TS=1000HZ)
T1(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW)
T2(Resp=N)
T3(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW)
T4(Resp=Y%DF=Y%W=0%ACK=O%Flags=Option -O and -osscan-guess also helps to discover OS
R%Ops=)
T5(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
T6(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=)
T7(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
PU(Resp=Y%DF=N%TOS=C0%IPLEN=164%RIPTL=148%RID=E%RIPCK=E%UCK=E%ULEN=134%DAT=E)

Uptime 0.221 days (since Mon Nov 11 12:22:16 2013)

Nmap finished: 1 IP address (1 host up) scanned in 11.064 seconds
You have new mail in /var/spool/mail/root

11. Scan a Host to Detect Firewall

The below command will perform a scan on a remote host to detect if any packet filters or Firewall is used by host.

[root@server1 ~]# nmap -sA 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:27 EST
All 1680 scanned ports on server2.tecmint.com (192.168.0.101) are UNfiltered
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.382 seconds
You have new mail in /var/spool/mail/root

12. Scan a Host to check its protected by Firewall

To scan a host if it is protected by any packet filtering software or Firewalls.

[root@server1 ~]# nmap -PN 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:30 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.399 seconds

13. Find out Live hosts in a Network

With the help of “-sP” option we can simply check which hosts are live and up in Network, with this option nmap skips port detection and other things.

[root@server1 ~]# nmap -sP 192.168.0.*

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 11:01 EST
Host server1.tecmint.com (192.168.0.100) appears to be up.
Host server2.tecmint.com (192.168.0.101) appears to be up.
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)
Nmap finished: 256 IP addresses (2 hosts up) scanned in 5.109 seconds

14. Perform a Fast Scan

You can perform a fast scan with “-F” option to scans for the ports listed in the nmap-services files and leaves all other ports.

[root@server1 ~]# nmap -F 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:47 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1234 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.322 seconds

15. Find Nmap version

You can find out Nmap version you are running on your machine with “-V” option.

[root@server1 ~]# nmap -V

Nmap version 4.11 ( http://www.insecure.org/nmap/ )
You have new mail in /var/spool/mail/root

16. Scan Ports Consecutively

Use the “-r” flag to don’t randomize.

[root@server1 ~]# nmap -r 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:52 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.363 seconds

17. Print Host interfaces and Routes

You can find out host interface and route information with nmap by using “–iflist” option.

[root@server1 ~]# nmap --iflist

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:07 EST
************************INTERFACES************************
DEV  (SHORT) IP/MASK          TYPE     UP MAC
lo   (lo)    127.0.0.1/8      loopback up
eth0 (eth0)  192.168.0.100/24 ethernet up 08:00:27:11:C7:89

**************************ROUTES**************************
DST/MASK      DEV  GATEWAY
192.168.0.0/0 eth0
169.254.0.0/0 eth0

In above output, you can see that map is listing interfaces attached to your system and their respective routes.

18. Scan for specific Port

There are various options to discover ports on remote machine with Nmap. You can specify the port you want nmap to scan with “-p” option, by default nmap scans only TCP ports.

[root@server1 ~]# nmap -p 80 server2.tecmint.com

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:12 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
PORT   STATE SERVICE
80/tcp open  http
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) sca

19. Scan a TCP Port

You can also specify specific port types and numbers with nmap to scan.

[root@server1 ~]# nmap -p T:8888,80 server2.tecmint.com

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:15 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
PORT     STATE SERVICE
80/tcp   open  http
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.157 seconds

20. Scan a UDP Port

[root@server1 ~]# nmap -sU 53 server2.tecmint.com

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:15 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
PORT     STATE SERVICE
53/udp   open  http
8888/udp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.157 seconds

21. Scan Multiple Ports

You can also scan multiple ports using option “-p“.

[root@server1 ~]# nmap -p 80,443 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 10:56 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
PORT    STATE  SERVICE
80/tcp  open   http
443/tcp closed https
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.190 seconds

22. Scan Ports by Network Range

You can scan ports with ranges using expressions.

[root@server1 ~]#  nmap -p 80-160 192.168.0.101

23. Find Host Services version Numbers

We can find out service’s versions which are running on remote hosts with “-sV” option.

[root@server1 ~]# nmap -sV 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:48 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE VERSION
22/tcp   open  ssh     OpenSSH 4.3 (protocol 2.0)
80/tcp   open  http    Apache httpd 2.2.3 ((CentOS))
111/tcp  open  rpcbind  2 (rpc #100000)
957/tcp  open  status   1 (rpc #100024)
3306/tcp open  mysql   MySQL (unauthorized)
8888/tcp open  http    lighttpd 1.4.32
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 12.624 seconds

24. Scan remote hosts using TCP ACK (PA) and TCP Syn (PS)

Sometimes packet filtering firewalls blocks standard ICMP ping requests, in that case, we can use TCP ACK and TCP Syn methods to scan remote hosts.

[root@server1 ~]# nmap -PS 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:51 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.360 seconds
You have new mail in /var/spool/mail/root

25. Scan Remote host for specific ports with TCP ACK

[root@server1 ~]# nmap -PA -p 22,80 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:02 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
PORT   STATE SERVICE
22/tcp open  ssh
80/tcp open  http
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.166 seconds
You have new mail in /var/spool/mail/root

26. Scan Remote host for specific ports with TCP Syn

[root@server1 ~]# nmap -PS -p 22,80 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:08 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
PORT   STATE SERVICE
22/tcp open  ssh
80/tcp open  http
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.165 seconds
You have new mail in /var/spool/mail/root

27. Perform a stealthy Scan

[root@server1 ~]# nmap -sS 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:10 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.383 seconds
You have new mail in /var/spool/mail/root

28. Check most commonly used Ports with TCP Syn

[root@server1 ~]# nmap -sT 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:12 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
111/tcp  open  rpcbind
957/tcp  open  unknown
3306/tcp open  mysql
8888/tcp open  sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 0.406 seconds
You have new mail in /var/spool/mail/root

29. Perform a tcp null scan to fool a firewall

[root@server1 ~]# nmap -sN 192.168.0.101

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 19:01 EST
Interesting ports on server2.tecmint.com (192.168.0.101):
Not shown: 1674 closed ports
PORT     STATE         SERVICE
22/tcp   open|filtered ssh
80/tcp   open|filtered http
111/tcp  open|filtered rpcbind
957/tcp  open|filtered unknown
3306/tcp open|filtered mysql
8888/tcp open|filtered sun-answerbook
MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems)

Nmap finished: 1 IP address (1 host up) scanned in 1.584 seconds
You have new mail in /var/spool/mail/root

That’s it with NMAP for now, I’ll be coming up more creative options of NMAP in our second part of this serious. Till then, stay tuned with us and don’t forget to share your valuable comments.

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Tarunika
I am a linux server admin and love to play with Linux and all other distributions of it. I am working as System Engineer with a Web Hosting Company.

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37 Comments

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  3. Hello,

    I was doing udp port scanning on nmap .I have some udp ports open but in nmap it is showing open | filtered only. Please give me solution for this. Is there any other tool for this?

    Reply

  5. What is the best way to go about finding all ports being used by MySQL for clustering purposes?

    I am on Linux platform with MySQL NDB 5.7. I am trying to monitor all traffic related to MySQL clustering – between data nodes, management node and sql nodes. To that end, I used netstat to list all open ports listening on my machine before starting MySQL cluster. Then, I started MySQL cluster and ran netstat again. I assumed that the ports that were listening the second time around, but not the first time, were related to MySQL clustering.

    But there are two problems with this. First, there could be ports opened by other processes between the two netstat runs. Second, MySQL might open other ports after I ran the netstat command the second time.

    What is the best way to go about finding all ports being used by MySQL for clustering purposes? I believe ephemeral ports are picked dynamically, so perhaps if I knew all the MySQL clustering related processes that would be running, I can figure out every port that they are using. Pointers will be very welcome.

    Reply

  8. Good article, but using a version of Nmap many versions behind. Also should review the NSE ( NMAP SCRIPTING ENGINE) , very powerful.
    Version 7 of nmap brings a lot of interesting features to the table.

    Reply

    • @Bustdathing,

      Thanks for updating about NSE (NMAP SCRIPTING ENGINE).. never heard about it…Let me check and see what kind of other features its provides than standard Nmap..

      Reply

    • @KLR,
      Yes I agree, but this article was published almost 2 years back i.e. December 11, 2013, and last update was on January 3, 2015..

      Reply

  13. Hi,
    Great article! with loads precise information.

    Just one question, can we use any commands, while scanning NMAP ports for e.g. if ‘v’ is pressed, it increases the verbosity. If you know any please share!!:)!

    Thanks

    Reply

  18. Nice one.. Much helpful.
    It will be great if you can write some tricks for real time scanning and its limitation plus advantages.

    Reply

  22. Hi Tarunika,

    Its really amazing, after reading no doubt will remain in ur mind regarding NMAP.
    Will wait for next topic.

    Thank you.

    Reply

  23. Good tutorial and very help full . and also I need your help below was my target internal ip it using lot of bandwidth I need its host name for blocking .How can i use I use your entire tut

    nadeen@testlab:~$ sudo nmap -PS 10.210.12.15

    Starting Nmap 5.21 ( http://nmap.org ) at 2014-02-17 10:15 IST
    Nmap scan report for 10.210.12.15
    Host is up (0.038s latency).
    All 1000 scanned ports on 10.210.12.15 are closed
    MAC Address: 18:E2:C2:B2:37:F6 (Unknown)

    Nmap done: 1 IP address (1 host up) scanned in 19.74 seconds
    nadeen@testlab:~$

    Reply

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