How to check if port is in use on Linux or Unix

onebuck · 11-17-2016, 08:21 AM

Hi,

How to check if port is in use on Linux or Unix

Quote:

How do I determine if a port is in use under Linux or Unix-like system? How can I verify which ports are listening on Linux server?

It is important you verify which ports are listing on the server’s network interfaces. You need to pay attention to open ports to detect an intrusion. Apart from an intrusion, for troubleshooting purposes, it may be necessary to check if a port is already in use by a different application on your servers. For example, you may install Apache and Nginx server on the same system. So it is necessary to know if Apache or Nginx is using TCP port # 80/443. This quick tutorial provides steps to use the netstat, nmap and lsof command to check the ports in use and view the application that is utilizing the port.

Hope this helps.
Have fun & enjoy!

Disillusionist · 11-17-2016, 09:22 AM

stupidly thought this was a question!

Must pay more attention!

szboardstretcher · 11-17-2016, 09:31 AM

Very nice. I use 'ss' for quick access to used ports. Less typing.

onebuck · 11-17-2016, 02:24 PM

Hi,

Quote:

Originally Posted by Disillusionist

stupidly thought this was a question!

Must pay more attention!

I normally will post informational articles that some users are not aware of or learn from this type of information so they know how to do some Linux works by reference.

Quote:

"Knowledge is of two kinds. We Know a subject ourselves, or we know where we can find information upon it."- Samuel Johnson

No harm, everyone slips on occasions.

Have fun & enjoy!