How to install nmap on Ubuntu/Debian systems

# sudo apt-get install nmap

Install nmap in yum packaged system Centos/RHEL

# yum install nmap -y

Install from rpm package

# rpm -ivh nmap{version_of_package}.deb

Install from .deb package file you have downloaded

# dpkg -i nmap{version_of_package}.deb

Scan a single host

# nmap ubuntu.example.com

Scan a hostname for more information about the host

# nmap -v ubuntu.example.com

Scan multiple IP Addresses

# nmap 192.168.1.77 192.168.1.99

Scan range of IP addresses using wildcard (*)

# nmap 192.168.1.*

Scan entire subnet 255.255.255.0

# nmap 192.168.1.0/24

Scan for range of IPs

# nmap 192.168.1.33-99

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

Scan for particular port number

# nmap -p 22 192.168.1.99

Scan for TCP port 443

# nmap -p T:443 192.168.1.99

Scan for UDP port 82

# nmap -p U:82 192.168.1.99

Scan multiple ports

# nmap -p 443,82 192.168.1.99

Scan for all ports using wildcard(*)

# nmap -p "*" 192.168.1.99

To watch the all packets send and receiving

# nmap --packet-trace 192.168.1.77

Know whether a host is protected by firewall or not :
To scan firewall protected for a host

# nmap -PN 192.168.1.99

Scan firewall protected for a network

# nmap -sA 192.168.1.77

To know the interface and route

# nmap --iflist

Exclude single host

# nmap 192.168.1.10-100 --exclude 192.168.1.77

Exclude 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

To know more commands use command man

# man nmap