As with netstat, the ss command is use to display network information on Linux systems. the ss command is installed as a replacement for netstat. Netstat is not install on Ubuntu by default. The command above using grep shows port 22 only and sshd service is listening on that port. However, if you only want to see a specific service name or port, you can use the netstat command with the option above with grep.Įxample below shows you to scan for open ports and only list port 22. That should give you a lot of information. Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name When you run the command above with the options, you should see similar lines as below: Active Internet connections (only servers)

-p Show the PID and name of the listener’s process.

-n Show numerical addresses instead of resolving hosts.

If you want to list all ports available on a server, you run the commands below:įor detail command options, view the bullet below: If you don’t already netstat tool installed, use the commands below to install it. Netstat is a command-line tool that can provide information about network connections, including IP addresses, ports and services communicating on these ports. To identify listening ports on Ubuntu follow the steps below: Use the netstat Command Network port is identified by its number, the associated IP address, and the type of the communication protocol such as TCP or UDP. Since you can’t have two services listening on the same port, it’s a good chance that you may have ports that you’re probably not using and you’ll want to close them. The steps below will show you how to use some of these commands to identify listening ports and how find them. Ubuntu comes with some default commands that can be used to scan your servers for open ports. In some cases, ports that are not in use will stay open which may lead to them being exploited. Most servers built for public access will have services on them which listen on their assigned ports for communication. If you’re a server administrator or webmaster and want to make sure only approved ports are opened on your Ubuntu Linux server, the steps below should come in handy. This brief tutorial shows students and new users how to find all ports in use or listening ports when using Ubuntu Linux systems.

Ubuntu list serial port