Find Out What Ports Are Listening / Open On My Linux & FreeBSD Server

To find out what ports are listening or open on your Linux or FreeBSD server, you can use one of the following methods:

1. Use the "netstat" command: "netstat" is a command-line utility that allows you to view the network connections and statistics of your system. To list all the listening ports on your server using "netstat", follow these steps:
   2. Open a terminal and type the following command:

   netstat -tulpn

   3. The output of the "netstat" command includes a list of active network connections and their respective details, such as the protocol, the local and remote addresses, and the status. For example:

   Active Internet connections (only servers)
   Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
   tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      868/sshd
   tcp        0      0 0.0.0.0:25              0.0.0.0:*               LISTEN      890/master
   tcp6       0      0 :::22                   :::*                    LISTEN      868/sshd
   udp        0      0 0.0.0.0:68              0.0.0.0:*                           773/dhclient
   udp        0      0 0.0.0.0:111             0.0.0.0:*                           764/rpcbind
   udp        0      0 0.0.0.0:631             0.0.0.0:*                           887/cupsd
   udp        0      0 0.0.0.0:12345           0.0.0.0:*                           774/ntpd
   udp        0      0 0.0.0.0:5353            0.0.0.0:*                           774/ntpd
   udp6       0      0 :::12345                :::*                                774/ntpd
   udp6       0      0 :::5353                 :::*                                774/ntpd

   4. The "Local Address" column shows the local IP address and port of the connection. The "Proto" column shows the protocol used by the connection (e.g., "tcp", "udp"). The