mi hanno consigliato:

-trovare gli IP collegati al pc
netstat |grep ESTABLISHED

-controllare porte aperte:
netstat -na | grep LISTEN | grep ^tcp | cut -d: -f2 | cut -d" " -f1

-quali programmi le usano:
for i in $(netstat -na | grep LISTEN | grep ^tcp | cut -d: -f2 | cut -d" " -f1) ; do fuser -n tcp $i; done| grep -v ^here


oppure c'e':
ntop (display top network users)

iftop (display bandwidth usage on an interface by host)