command to know all used ports code example
Example 1: find out process using port windows
netstat -ano | findstr 8080
Example 2: how to check listening ports on a server
$ sudo netstat -plnt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 3686/mysqld
tcp 0 0 :::443 :::* LISTEN 2218/httpd
tcp 0 0 :::80 :::* LISTEN 2218/httpd
tcp 0 0 :::22 :::* LISTEN 1051/sshd
Example 3: how to check listening ports on a server
sudo ss -tulwn | grep LISTEN