traceroute (command)

View the route that an IP packet follows from one host to the next using the time-to-live (TTL).
The packet counts the number of hops in the route taken.
It uses ICMP packets to map the route. Use nmap instead (uses the TCP protocol instead, nearly every firewall allows it).

Trace the route to the URL

URL=www.google.com
traceroute $URL

See where the packet stops (router, firewall, etc.)

traceroute -T -p $PORT -q 1 -w 1 -n $IP