How traceroute works
Traceroute discovers the path network packets take from source to destination. It sends packets with incrementally increasing TTL (Time To Live) values. When a packet's TTL reaches zero, the router that received it sends back an ICMP "time exceeded" message, revealing its IP address and round-trip time.
What each hop tells you
Each line in a traceroute result is one hop — a router or device along the path. The response time shown is the round-trip time (RTT) from the source to that hop. High latency at a specific hop points to a bottleneck or congested link at that point in the network path.
Why some hops show * * *
Asterisks indicate a router that did not respond to the probe — either configured to drop or rate-limit ICMP packets, or filtering the probe. A non-responding hop does not mean the path is broken; packets can still pass through without generating a reply.
Common use cases
- Diagnosing slow connections — identify which network segment introduces the most latency.
- Confirming routing paths — verify that traffic routes through expected CDN or peering points.
- Isolating packet loss — compare RTT consistency across hops to find where loss is introduced.