A command line utility on Unix and NT (known as tracert) to know the hops and the IPs of the routers between the source and the destination.

Utilizes multiple icmp packets being sent towards the source with varied TTL numbers.

• First it will be set to 1, then each subsequent packet will have it incremented by 1.
• each time the router will send a reply with the Time Exceeded in transit command (Type = 11, Code = 0).