Here all the active TCP connections are listed by this fields:
Source IP: Remote machine that has a connection to the server;
Source port: Port used by the source machine;
Destination IP: Server IP;
Destination port: Port where the source machine is connected;
State: The default is enabled.
In Action, choose the option Block connection to finish a specific connection. After blocking one connection it's possible to unblock it hiting the option Unblock connection (Figure7.70).