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Killing Open Ports in Linux

Posted on 27 Jan, 2020
I had this weird error while running Django Development Server.
System check identified no issues (0 silenced).
January 27, 2020 - 16:42:39
Django version 2.2.9, using settings 'codeclassroom.settings'
Starting development server at
Quit the server with CONTROL-C.
Error: That port is already in use.


  1. 1.
    Run netstat -ntlp to see available open ports.
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0* LISTEN -
tcp 0 0* LISTEN -
tcp 0 0* LISTEN -
tcp 0 0* LISTEN -
tcp 0 0* LISTEN 12054/python3
tcp6 0 0 ::1:631 :::* LISTEN -
Here is a man netstat for what it does
netstat - Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships
You see the python3 one? Kill 😈 this process
  1. 2.
    Run kill -9 12054 Kill is used for Removing a background process or job, -9 specifies SIGKILL (Forced termination) where 12054 is the PID
  2. 3.
    Run the development server again.