These are for DNS and Internet Printing Protocol, respectively. You’ll also see that the ss output shows ports 53 and 631 are in a listening state. These are the well known ports associated with HTTP and MySQL. We can see that our server is listening for connections on port 80, 3306, and 33060. State Recv-Q Send-Q Local Address:Port Peer Address:Port Process Let’s look at an example on our test system. We recommend using the -ltn options with the command to see concise and relevant output. You can still install and use the netstat command to check for open ports as well. The ss command replaced the older netstat command on Linux. $ – requires given linux commands to be executed as a regular non-privileged user # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command Privileged access to your Linux system as root or via the sudo command. Requirements, Conventions or Software Version Used How to show/check for open ports on Ubuntu Linux Software Requirements and Linux Command Line Conventions Category How to check for and add allowed ports in ufw firewall.How to check for open ports with Nmap utility.How to check for open ports with ss command.So, do you know which ports of your system are open? Let’s find out. We’ll also see how to use Ubuntu’s ufw firewall to make sure ports are secure. This can be done with several different command line utilities, which we’ll go over in detail. In this tutorial, we’ll see how to check for open ports on Ubuntu Linux. Otherwise, you could be unaware of outside connections being made to your computer, which consumes bandwidth and resources, along with being a potential security hole. As a Linux administrator or user, it’s important to always know which ports of your system are open to the internet. A simple example would be a web server, which handles user requests whenever someone navigates to a website.

Some Linux software works by listening for incoming connections. Checking for open ports on Ubuntu Linux is an essential part of security administration.

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