How to Determine which Process or Application uses a TCP Connection
This recipe shows how to determine which process or application uses a TCP connection which you saw listed in your netstat output. The exampe below is for Linux. Windows is further down in the post:
In this example, I have a small ARM Linux device being remotely managed via the “Dataplicity” service. To use the service you install a script which runs on startup. It seems that the script sets up an SSH connection from the managed ARM device to the dataplicity server, so that when you login to their Admin portal and choose the “terminal” option, you access the Linux terminal which is already setup.
The netstat output shows a session outbound from the ARM machine (10.10.0.126) to the dataplicity server (96.126.99.204) on TCP/443 (SSL):
root@raspberrypi:/# netstat -an | grep ‘:443’
tcp 0 48 10.10.0.126:46098 96.126.99.204:443 ESTABLISHED
the next step is to find which process(es) use the (source) TCP port 46098:
