Traceroute guide & command generator

What traceroute does

Traceroute maps the path your packets take across the internet to reach a destination, listing every router (hop) in between along with the round-trip time to each. It's the first tool to reach for when a site is slow or unreachable, because it shows where the trouble starts.

How it works

It sends packets with a deliberately small Time To Live (TTL), starting at 1. Each router decrements the TTL; when it hits zero, the router replies with a "time exceeded" message that reveals its address. By increasing the TTL one step at a time, traceroute discovers each hop in order.

Reading the output

• Each numbered line is one hop, usually showing three timing samples in milliseconds.
• Rising latency is normal as distance grows. A sudden, sustained jump points to the congested or distant link.
• Asterisks (* * *) mean a router didn't reply — often harmless (some devices deprioritise these packets), but persistent stars to the end can indicate a block or outage.
• The final line should be your destination. If it never arrives, the problem is at the last responding hop or beyond.

Handy variations

• tracert -d example.com (Windows) — skip DNS lookups for faster results.
• traceroute -I example.com (Linux) — use ICMP like Windows does.
• traceroute -T -p 443 example.com — trace using TCP to port 443 when firewalls block UDP/ICMP.
• mtr example.com — a live, continuously updating traceroute (install on Linux/macOS).