List Network Ports on Linux Based Operating Systems
===================================================

Author: Momchil Ivanov <momchil@xaxo.eu>
Date  : 2021.03.25

Introduction
------------

This article describes different methods on how to list network ports
on Linux based operating systems.

Using netstat
-------------

List all sockets:

$ netstat -na

List all TCP sockets:

$ netstat -tna

List all listening TCP sockets:

$ netstat -tnl

List all listening TCP and UDP sockets:

$ netstat -tnlu

To list all listening TCP and UDP sockets and the corresponding
processes holding the socket:

$ netstat -tnlpu

List additional information:

$ netstat -tnlpe

Using ss
--------

List all TCP sockets:

$ ss -nta

List all listening TCP sockets:

$ ss -lnt

List all listening TCP and UDP sockets:

$ ss -lntu

List all listening TCP and UDP sockets and the corresponding processes
holding the sockets:

$ ss -lntup

Using lsof
----------

List all sockets:

$ lsof -i

List all listening TCP sockets (needs root):

# lsof -iTCP -sTCP:LISTEN -n -P

List all listening TCP sockets over IPv4 (needs root):

# lsof -i4TCP -sTCP:LISTEN -n -P