centos查看端口命令

netstat -tuln

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     
tcp6       0      0 :::22                   :::*                    LISTEN     
udp        0      0 0.0.0.0:123             0.0.0.0:*                          

ss -tuln

State      Recv-Q Send-Q Local Address:Port                 Peer Address:Port              
LISTEN     0      128              *:22                           *:*                  
LISTEN     0      128             :::22                          :::*                  
UNCONN     0      0              *:123                           *:*                  

lsof -i :端口号

lsof -i :80

COMMAND   PID   USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
nginx   1234   root    6u  IPv4  12345      0t0  TCP *:http (LISTEN)

nmap localhost

nmap -p 1-65535 localhost

Starting Nmap 7.91 ( https://nmap.org ) at 2023-04-01 12:34 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000080s latency).
Not shown: 997 closed ports
PORT   STATE SERVICE
22/tcp open  ssh
80/tcp open  http
443/tcp open https