Traceroute is a command-line tool used to identify the route taken by packets across an IP network. It operates by sending a series of packets to a specified destination host, with each packet containing a different Time to Live (TTL) value. As each packet traverses a router, the TTL is decremented by 1. When the TTL reaches 0, the router discards the packet and sends an Internet Control Message Protocol (ICMP) Time Exceeded message back to the source host. Traceroute uses the ICMP Time Exceeded messages to determine the path taken by the packets and the latency (time delay) at each hop along the route.
Traceroute is a valuable tool for network troubleshooting and performance analysis. It can be used to identify network congestion, packet loss, and other issues that may be affecting network performance. Traceroute can also be used to verify the path taken by packets between two hosts and to identify the location of network bottlenecks.