When you run a traceroute (or tracert on Windows), you are essentially mapping out the route your data takes across the internet's "backbone" routers.

The Secret of Time Exceeded

Traceroute relies on a field in IP packets called Time To Live (TTL). Every time a router receives a packet, it subtracts 1 from the TTL. If the TTL reaches zero, the router discards the packet and sends an ICMP "Time Exceeded" message back to you.

The Hop-by-Hop Process

  1. Traceroute sends a packet with TTL=1. The first router drops it and replies. You now know "Hop 1".
  2. It sends another with TTL=2. The second router drops it. You have "Hop 2".
  3. This continues until the destination is reached.

Reading the Results

In your traceroute result, each line shows the IP, hostname, and three latency measurements (RTT). High latency at a specific hop often indicates a congested network link or a routing bottleneck.