If a network condition prevents traceroute from reaching the destination
Common reasons for traceroute
failing to reach a destination include:
Timeouts (indicated by one asterisk per probe, per hop)
Unreachable hosts
Unreachable networks
Interference from firewalls
Hosts configured to avoid responding
Executing traceroute
where the route becomes blocked or otherwise fails results
in an output marked by timeouts for all probes beyond the last detected
hop. For example, with a maximum hop count of 7 (maxttl
= 7), where the route becomes blocked or otherwise fails, the output
appears similar to this: