Nmap Commands for System Admins and Network Admins

Nmap [Network Mapper] is a free and open source utility for network discovery and security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.

Here from this Post we can learn most of the useful command with option of nmap to scan the network and network ranges , single host , Os information and much more

It will Show which machines are up in network It will show which machine has which Operating system It will show which ports all opened We can Scan for a Range if networks

How to install nmap Ubuntu/Debain systems

sudo apt-get install nmap

This will install the nmap package ..

Scan a Single IP Address

scan a single IP Address

nmap 192.168.1.99

output

root@ubuntu:~# nmap 192.168.1.99

Starting Nmap 5.21 ( http://nmap.org ) at 2013-10-26 11:12 IST Nmap scan report for 192.168.1.99 Host is up (0.00057s latency). Not shown: 998 closed ports PORT STATE SERVICE 21/tcp open ftp 22/tcp open ssh MAC Address: 00:24:1D:B8:7B:8D (Giga-byte Technology Co.)

Nmap done: 1 IP address (1 host up) scanned in 0.24 seconds

scan a single host

nmap ubuntu.example.com

root@ubuntu:~# nmap ubuntu.example.com

Starting Nmap 5.21 ( http://nmap.org ) at 2013-10-26 11:13 IST Nmap scan report for ubuntu.example.com (192.168.1.160) Host is up (0.0000070s latency). Not shown: 996 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 389/tcp open ldap 443/tcp open https

Nmap done: 1 IP address (1 host up) scanned in 0.12 seconds

scan a hostname for more information about the host

nmap -v ubuntu.example.com

Here is the Output

root@ubuntu:~# nmap -v ubuntu.example.com

Starting Nmap 5.21 ( http://nmap.org ) at 2013-10-26 11:14 IST Initiating SYN Stealth Scan at 11:14 Scanning ubuntu.example.com (192.168.1.160) [1000 ports] Discovered open port 80/tcp on 192.168.1.160 Discovered open port 443/tcp on 192.168.1.160 Discovered open port 22/tcp on 192.168.1.160 Discovered open port 389/tcp on 192.168.1.160 Completed SYN Stealth Scan at 11:14, 0.07s elapsed (1000 total ports) Nmap scan report for ubuntu.example.com (192.168.1.160) Host is up (0.000021s latency). Not shown: 996 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 389/tcp open ldap 443/tcp open https

Read data files from: /usr/share/nmap Nmap done: 1 IP address (1 host up) scanned in 0.16 seconds Raw packets sent: 1000 (44.000KB) | Rcvd: 2004 (84.176KB)

Scan Multiple IP Address

Scanning multiple IPs

nmap 192.168.1.77 192.168.1.99

or

nmap 192.168.1.77,99

Output is Here

root@ubuntu:~# nmap 192.168.1.77 192.168.1.99

Starting Nmap 5.21 ( http://nmap.org ) at 2013-10-26 11:15 IST Nmap scan report for 192.168.1.77 Host is up (0.00086s latency). Not shown: 995 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 443/tcp open https 3000/tcp open ppp 5432/tcp open postgresql MAC Address: 00:24:7E:00:ED:79 (USI)

Nmap scan report for 192.168.1.99 Host is up (0.00073s latency). Not shown: 998 closed ports PORT STATE SERVICE 21/tcp open ftp 22/tcp open ssh MAC Address: 00:24:1D:B8:7B:8D (Giga-byte Technology Co.)

Nmap done: 2 IP addresses (2 hosts up) scanned in 6.16 seconds

Scanning Range of IP using Wildcard (*)

nmap 192.168.1.*

Output is too long so avoided it here

Scanning Entire Subnet 255.255.255.0

nmap 192.168.1.0/24

Scanning for range of IPs

nmap 192.168.1.33-99

Here is the Output

To Find the OS & Version of remote Hosts Using Nmap

nmap -A 192.168.1.77

This will output more information about a Host and its Ports and Operating systems and Version

nmap -v -A 192.168.1.77

Show more information with Vebrosity

To scan a Particular Ports

Syntax :

nmap -o port_number hostname(or)IPaddress

scanning for particular Port number

nmap -p 22 192.168.1.99

Output is here

root@ubuntu:~# nmap -p 22 192.168.1.99

Starting Nmap 5.21 ( http://nmap.org ) at 2013-10-26 11:18 IST Nmap scan report for 192.168.1.99 Host is up (0.00056s latency). PORT STATE SERVICE 22/tcp open ssh MAC Address: 00:24:1D:B8:7B:8D (Giga-byte Technology Co.)

Nmap done: 1 IP address (1 host up) scanned in 0.16 seconds

scanning for TCP ports 443

nmap -p T:443 192.168.1.99

scanning for UDP ports 82

nmap -p U:82 192.168.1.99

scanning multiple ports

nmap -p 443,82 192.168.1.99

#scanning for all ports using wildcard(*)

nmap -p "*" 192.168.1.99

To Watch the all packets send and reciving

nmap --packet-trace 192.168.1.77

Know Whether a Host is Protected by Firewall or not :

To scan firewall protcted for a host

nmap -PN 192.168.1.99

To scan firewall protected for a Network

nmap -sA 192.168.1.77

To know the interface and Route

nmap --iflist

Output is here

root@ubuntu:~# nmap --iflist

Starting Nmap 5.21 ( http://nmap.org ) at 2013-10-26 11:19 IST INTERFACES DEV (SHORT) IP/MASK TYPE UP MAC lo (lo) 127.0.0.1/8 loopback up eth0 (eth0) 192.168.1.160/24 ethernet up 00:15:5D:01:11:39

ROUTES DST/MASK DEV GATEWAY 192.168.1.0/0 eth0 0.0.0.0/0 eth0 192.168.1.1

scan a List of hosts and networks from a text file

cat > /home/sysadmin/ips.txt

File contain IPs and Hosts are here

192.168.1.77 192.168.1.99 192.168.1.0/24 ubuntu.example.com

To scan the network using created file use command

nmap -iL /home/sysadmin/ips.txt

While scanning a Bunch of hosts , If we need to Drop any one of the host or multiple hosts

Excluding Single host

nmap 192.168.1.10-100 --exclude 192.168.1.77

Excluding Multiple Hosts

nmap 192.168.1.10-100 --exclude 192.168.1.77,192.168.1.95,192.168.1.99

To Perform a Fast scan

nmap -F 192.168.1.77

Output Here

11.Use command man

man nmap

This will show all the available options for nmap and u can learn more about nmap