Nmap is simple and practical

nmap Is a port scanning tool And telnet The difference is It can scan all open ports of the specified host （ Intranet ） More tools, more happiness Here are some basic usage These are enough for operation and maintenance

download

direct yum Installation is over

yum install  nmap -y

Scan all ports of the target host

nmap $ip

Scan the specified port of the target host

[[email protected] ~]# nmap -n --open -p 8080 10.251.128.9

Starting Nmap 6.40 ( http://nmap.org ) at 2020-11-19 16:44 CST
Nmap scan report for 10.251.128.9
Host is up (0.0092s latency).
PORT     STATE SERVICE
8080/tcp open  http-proxy

Nmap done: 1 IP address (1 host up) scanned in 0.09 seconds

Scan the entire network segment host of the intranet

nmap 10.0.0.0/24