netstat

Displays active TCP connections, ports on which the computer is listening, Ethernet statistics and more

Ver as conexões ativas

# COMMAND
netstat -nlpt

# OUTPUT SAMPLE
(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      0 127.0.0.1:9050          0.0.0.0:*               LISTEN      -