Finding Abusive Users with netstat

If you run any type of service accessible from the Internet, sooner or later someone will abuse it. You'll notice it by a slow response from your server, increased bandwidth usage, or a total denial of service. You can solve this problem manually each time it happens, or you can write a script that helps identify and block access to the abusers.

Whenever someone makes a connection to your server, the connection can be listed with the netstat command. I will demonstrate how to use this command to locate troublesome users.