The Joy of Linux commands--nmap

Nmap is a very powerful utility that can be used to: Detect host (host discovery) live on the network The Open port (port Discovery or enumeration) detects the appropriate port (service discovery) software and version detection operating system, hardware address, and software version detection vulnerability

Parameters:

< target > can be a standalone IP, a host name or a subnet
-ss TCP SYN Scan (also known as half-open or covert scan)
The-P0 option allows you to turn off ICMP pings
-SV option Enable version detection
-O indicates an attempt to identify the remote operating system
Other options:
-A option to enable OS fingerprint and version detection
-V use two times-V to view detail information

1. Query the machine open port and service status and MAC address, the latter can be connected to multiple IP or a network segment

Check the service status of the specified port, which can be written in script as a method of monitoring service

2. Querying the type of computer system in a network segment

The Joy of Linux commands--nmap