Nmap is a network scanner.
Nmap is used to discover hosts and services on a computer network by sending packets and analyzing the responses.
Nmap provides a number of features for probing computer networks, including host discovery and service and operating system detection.
Check most commonly used Ports with TCP Syn
Find Host Services version Numbers
Perform a Fast Scan plus OS and version detection
Perform a TCP null scan to fool a firewall
Perform a Slow comprehensive scan
Print Host interfaces and Routes
Scan a Host to Detect a Firewall
Scan a Host to check it is protected by a Firewall
Scan Hostname using "-v" option
Scan list of Hosts from a File
Scan Multiple Servers using last octet of IP address
Scan Network Excluding Remote Hosts
Scan OS information and Traceroute
Scan Remote host for specific ports with TCP ACK