traceroute does not work, output is * * * but network is fine [closed]

By default, traceroute uses high UDP ports for tracing hosts. However, sometimes firewalls block these UDP ports.

Try to add the -I (uppercase i) parameter to the command line, eg:

traceroute -I www.google.it

This will use ICMP instead of UDP for tracing hosts.

Try to use -T (tcp) or -U (udp) to bypass firewall.
Some routers/firewall don't let icmp echo pass trough, that's why you'd use those 2 to by pass them.
Anyway, contrary as stated in wikipedia, on my debian boxes traceroute still uses icmp packets and not udp.

EDIT

I was wrong...it uses udp...the icmp coming back are for an unreachable port...sorry