How can I check if a port is busy or if someone is using it?

How can I check if a port is busy or if someone is using it?

Netstat

  • Start > Run
  • Enter cmd
  • In the command console enter:
    netstat -ano | findstr portNumber
    This lists any processes where the port number is included somewhere on the line.
  • Look at the first number (in the second column). If this shows the port number after a colon, this means the port is currently being used.
  • Make a note of the number at the end of the line. This is the process ID (PID).
  • In the command console enter:
    tasklist | findstr PID
    and search for this PID

Info:

  • try port 63500 for go2MONITOR channel 1
  • you can also look up the PID in the task manager

TCPView

TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on your system, including the local and remote addresses and state of TCP connections

http://technet.microsoft.com/en-us/sysinternals/bb897437.aspx

Netcat

You can also try to open a port with netcat:

  • nc -l -p 63500

You will receive an error message, if the port can not be opened.

http://joncraton.org/blog/netcat-for-windows

Last update on 2018-05-12 by Rolf Haenggi.

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